第一篇:新人教版八年級英語下冊第三單元知識點
Unit3 Could you please clean your room? 一.情態(tài)動詞could 的用法
1.提出禮貌的要求 Could you please(not)do sth ?請你(做)......好嗎?
用于提出請求,希望得到對方的肯定回答,說話的語氣比較客氣委婉。Could 不是can的過去式,是委婉、禮貌的說法?;卮鹩胏an.肯定回答:Yes,sure./ Yes, I can./Of course,I can./ Certainly./No problem./ With pleasure.否定回答: Sorry , I can’t / I’m afraid I can’t.I have to …,I’m going to…(說明理由)2.表示請求許可 Could I do a sth? 我可以做......嗎?
肯定回答:Yes, you can./ Yes ,please / Of course / Certainly./ No problem.否定回答:Sorry , you can’t / I’m afraid you can’t.3.could 為can的過去式,表示過去的能力。= was / were able to
Section A 1.take out the rubbish把垃圾帶出去 2.do the dishes = wash the dishes 洗碗碟 3.fold your clothes折衣服 4.sweep the floor掃地 5.make your bed整理床鋪
6.clean the living room打掃起居室
7.do some washing/ shopping/ cleaning洗衣服/ 購物/ 做清潔 8.go out for dinner出去吃晚飯 9.go to the movies去看電影
10.stay out late/ until nine呆到很晚/ 呆到9點鐘 11.get a ride撘車
12.give sb a ride to town開車送sb到鎮(zhèn)上 13.need to do something需要做…… 14.have to do something不得不做…… 15.help out with a few things幫助做些事情
16.at least 至少,多指數(shù)量或程度上的最低限度。(反)at most 至多,不超過 17.finish doing something完成做……
18.two hours of TV 兩個小時的電視
表示時間、距離、金額、度量等詞語作主語時,被視作整體,謂動用單數(shù)。19.be/ come back from shopping購物回來 20.any minute/ second/ moment now隨時 21.be angry with…對……生氣 22.solve the problem解決問題
23.throw down扔下,隨手丟下。throw at 向…扔去(惡意)throw to …扔給 throw away 扔掉 24.the minute……/ as soon as… / the moment …一…….就……(引導(dǎo)時間狀語從句,主將從現(xiàn))25.come over 過來,順便來訪
26.take the dog for a walk= take a walk with … 遛狗 27.reply angrily生氣地回答
28.all the time一直
all day一整天
all evening整晚 29.shout back吼回去
talk back 頂嘴 neither / nor +助動詞/be動詞/情態(tài)動詞 +主語
“某人也不”
neither兩者都不
neither …nor… 既不…也不…(就近原則)
neither of us我們兩個都不 31 in surprise驚訝地
find +賓語+ adj / n./ prep 短語
find sb.doing sth 發(fā)現(xiàn)某人做某事
find it + adj.+ to do sth 發(fā)現(xiàn)做某事很……◆find it difficult/ hard to do sth 發(fā)現(xiàn)做某事很困難 33.share the housework分擔(dān)家務(wù)
share sth with sb.和某人分享某物 34.hang out with sb 和某人一起閑逛
hang up 把......懸掛/掛起 35.pass sb sth= pass sth to sb把某物遞給某人
Pass on 傳遞
36.borrow s from sb 從某人那里借某物 37.lend sth to sb = lend sb sth 把某物借給某人
keep……for +一段時間:借…一段時間 38.hate to do / doing sth討厭做……
39.try(not)to do sth努力(不)做某事。try one’s best to do sth= do one’s best to do sth 盡某人最大努力做某事
try on 試穿
try to do sth 努力做某事 【側(cè)重盡力做】
try doing sth 試圖做某事 【側(cè)重嘗試做】
40.while conj.“在……期間; 當(dāng)……的時候”
While 引導(dǎo)的時間狀語從句的謂語動詞只能是延續(xù)動詞.(進(jìn)行時)Section B 1.invite v → invitation n邀請(1)invite sb.to do sth 邀請某人做某事
(2)invite sb.to +地點 邀請某人去某地 2.enough stress from school來自于學(xué)校的足夠的壓力
under the stress of …在…的壓力之下 3.a waste of time浪費(fèi)時間 waste
v “浪費(fèi)”
waste time/money on sth /(in)doing sth 在。。浪費(fèi)時間/金錢 4.人:spend…… on sth
人:pay ……for sth
物 :sth cost sb +金錢
(in)doing sth
It takes sb +時間 to do sth.5.in order(not)to do sth為了做…… 6.get into a good university進(jìn)入好大學(xué)
7.there is no need for sb to do sth 對于某人來說沒必要做……
8.provide sth.for sb.= provide sb.with sth.為某人提供某物(為應(yīng)急等做好準(zhǔn)備而“提 供; 供給”)
offer sb.sth.= offer sth to sb.側(cè)重表示“愿意給予”
offer to do sth 主動提出干某事 Supply sb.with sth=supply sth.to sb.定期 “ 供應(yīng) ” , 強(qiáng)調(diào)替代或補(bǔ)充所需物品
9.depend on …依靠……依賴,由…而決定
10.develop children’s independence 養(yǎng)成孩子的獨立(習(xí)慣)→development → developed / developing 11.the idea of fairness公平意識
12.have no idea = don’t know 不知道 13.fall ill生病
14.grades drop成績下降
15.as a result因此,結(jié)果
as a result of …由于……作為……的結(jié)果
16.It’s fair/ unfair for sb to do sth 對于某人來說,做……是(不)公平的。17.get something to drink買飲料 18.be careful with… 小心對待…… 19.a few other things另處幾件事
20.Do one’s part(in)doing sth.盡自己的職責(zé)做某事 21.the earlier...the better…越早……越好…….【模擬試題】
一、英漢互譯。
1.play with ___________
2.have a test ___________ 3.do chores ___________
4.take out ___________ 5.make the bed ___________
6.sweep the floor ___________ 7.從……借___________
8.遛狗___________ 9.生氣___________
10.照顧___________ 11.邀請某人到……___________
12.忙于/從事___________ 13.洗餐具_(dá)__________
14.做飯___________
二、根據(jù)要求答題。
1.Could you help me clean the living room?(作肯定回答)_____________, ____________________.2.Thanks for taking care of my dog.(變同義句)_________________ for ________________ my dog.3.Remember to clean the bed.(改為同義句)________ ________ to clean the door.4.Can you lend your pen to me?(改為同義句)Can ________ ________ your pen? 5.I like to wash the plates because it’s relaxing.(就劃線部分提問)________ ________ you ________ to wash the plates?
三、用could, can, may, must, needn’t填空。
1.A: ________ you answer the question in English?
B: Sorry, I ________.________ I answer it in English?
A: No, you ________.You ________ answer it in Chinese.2.A: ________ I ask a question? B: Yes, you ________.But you ________ wait, a minute.3.A: ________ I use your eraser, Bill? B: Sorry.I don’t have one.Ask Mary.She _________ have one.4.A: ________ you help me do the shopping.B: OK, Sure.5.A: ________ you sweep the floor? B: But I ________ finish my homework first.四、單項填空。
1.—What a dirty room!You shouldn’t throw your waste things everywhere.-Oh, I am sorry, I am going to ________ and put them in the waste box.A.fold my clothes B.take out the trash C.watch TV 2.—Could you please go to the movies with me tonight? —Sorry, my mother is ill in bed, and I have to ______ her.A.take care of B.take a walk with C.take over 3.Don’t _________ the dog.it’s dangerous, it’ll bite you.A.play with B.play C.play for 4.—Jim, come out.Let’s go to play football.—Sorry.I’m _______ a maths problem.A.working out B.working on C.working for 5.—Mum, Could I go shopping with you? —Yes, ________ But you have to finish your homework first.A.you can B.you could C.you can’t 6.My mother often ________ my little sister _________ of the house and plays with her in the garden.A.take…out B.takes…out C.takes … to 7.I _________ doing the dishes because it’s boring.A.hates B.hate C.like 8.I _________ some money from him, but I’ll _______ it to him in a few days.A.borrow, return B.lend, borrow C.borrow, keep 9.________ the young trees is our duty.A.Taking good care of B.Take good care of C.Takes good care of
第二篇:新版八年級英語下冊第三單元知識點歸納
新版八年級英語下冊第三單元知識點歸納
Unit3 Could you please clean your room?
一、Peter ,could you please take out the rubbish? 彼得,你能把垃圾倒了嗎?----sure,mom.Could you please do sth ?請你(做)......好嗎? 用于提出請求,希望得到對方的肯定回答,說話的語氣比較客氣委婉。
Could 不是can的過去式,是委婉、禮貌的說法?;卮鹩胏an.【常用答語】肯定回答:Sure./ Of course./ Certainly./No problem.否定回答: Sorry , I can’t
2、take out 取出(v+ adv)
【注】: 跟代詞做賓語,代詞放中間;跟名詞做賓語,可放在中間,也可放在后邊 take 有關(guān)的短語: take out 帶出去,取出
Please take out a piece of paper.請拿出一張紙。
Please take it out.請把它拿出來。take...out “把??帶出去”
My father is taking me out to go for a drive.我爸爸要帶我出去開車。(1)take off 脫下;(飛機(jī))起飛
----Please take off your coat(外套), It’s warm here.---The plane took off at 9:00 am.【短語】take out the trash/rubbish 倒垃圾 take away 拿走,取走
take back 收回 take place 發(fā)生 take off 脫下; 起飛
(2)take ?to ?把...帶到...(3)take sb.for a walk 帶某人去散步 take a walk 散步(4)take exercise 運(yùn)動,鍛煉(5)take one’s time 不用急,慢慢來(6)take a bus(ship/train)乘坐公共汽車(7)take turns 輪流,替換(8)It takes sb.some time to do sth.做某事花費(fèi)某人多長時間 3.Can you do the dishes.?那你可以洗盤子嗎?
do the dishes 洗碗
【結(jié)構(gòu)1】do the +名詞: do the dishes/ laundry 洗餐具/衣服
【結(jié)構(gòu)2】do the +動詞-ing do the cleaning 打掃衛(wèi)生
【結(jié)構(gòu)3】do one’s + 名詞 do one’s housework/ homework 做家務(wù)/家庭作業(yè)
【結(jié)構(gòu)4】do some +動詞-ing do some reading/ shopping 讀寫書/購物 4.could you please help out with a few things? help out動詞短語,表示在某人繁忙或 遇到困難時“給予幫助”。
help和out之間還可以加入具體的“人”。
e.g.He helped me out with my task.他幫我完成了任務(wù)。
They helped(us)out with the clean-up.他們幫助我們做大掃除。
5.Because Mom will back from shopping any minute now.因為媽媽馬上回來購物。
6.any minute now 一種常見的口語表達(dá)法,相當(dāng)于“隨時;馬上;在任何時刻”的意思,e.g.Don’t worry, he will come here any minute now.別擔(dān)心, 他會馬上來這兒。7.Could I at least finish watching this show? 至少讓我看完這個節(jié)目可以嗎? 1】Could I do sth? 我可以做......嗎?
用于表達(dá)請求,語氣比較委婉。Could I go out with my classmate this weekend? 2】at least 至少,多指數(shù)量或程度上的最低限度。(反)at most 至多 3】finish v 結(jié)束;完成 finish doing sth 做完某事
eg— Can you finish reading these books before 10 o'clock? — Yes, I can.5、I think two hours of TV is enough for you!我覺得你看兩個小時的電視已經(jīng)足夠了。1】two hours of TV 表示時間、距離、金額、度量等詞語作主語時,通常被視作整體,謂語動詞用單數(shù)形式。
How time is flies!Three yearsisreally a short time.時光飛逝!三年真的是短暫的時光?!窘馕?】enough 足夠的,充分的(在句中作定語或表語)
I don’t have enough money with me.我沒有足夠的錢?!窘馕?】足夠;充分(放在形容詞;副詞后)
The river is deep enough for swimming.這條河夠深,可以游泳。
【記】 Mr.Smith has enough money ,but he isn’t kind enough to help others.史米斯先生有足夠的錢,但他不夠好心幫助別人
【注意】enough 修飾名詞時,置于名詞前;修飾形容詞時,置于形容詞之后。
6、Could you take out the rubbish,fold the clothes and do the dishes? 你能把垃圾倒了。把衣服疊好,再把碗洗了嗎? 【解析】take out 拿出;取出 take 的用法:
Please take some books to the classroom.請帶一些書到教室去。
Take this medicine three times a day.這藥一天服三次。They usually take the bus to work.他們通常乘公共汽車去上班。
It takes me two hours to do my homework every day.我每天花兩個小時做作業(yè)。短語 take a rest 休息 take care of 照顧 take off 脫下;起飛 take up 占據(jù)
take down 拿下 take one’s time 不急;慢慢來 take one’s temperature 量體溫 7.The minute I sat down in front of the TV, my mom came over.我剛坐在電視機(jī)前面,我媽媽就過來了。
【解析1】the minute = as soon as “一......就......”
Please write to me the minute you get there.【解析2】 in front of指在物體外部的前面
There is a bike in front of the classroom.教室前面有一輛自行車。指在物體內(nèi)部的前面
Our teacher is standing in the front of the classroom 我們的老師正站在教室的前面 【記】 The driver sat _in the front of_ the car.The policeman stood ___in front of_ the car.【注意】有the無the區(qū)別大:
at table 吃飯;進(jìn)餐 in hospital 住院
at the tabel 在桌邊 in the hospital 在醫(yī)院(不一定看?。窘馕?】come over 過來
【拓展】 come 短語:
come across(偶然)發(fā)現(xiàn) come back 回來 come up with想出 come true實現(xiàn) come down下來 come from=be from來自,出生于 come in/into進(jìn)入,進(jìn)來 come on趕快,加油 come along走吧,過來,快點 come and go來來去去 come up上來 come out出來,(花)開,(照片)沖洗出來 7.You watch TV all the time and never help out around the house!你總是看電視,從不幫忙做家務(wù)!
all the time = always 一直;總是
8.I’m just as tired as you are!我和你一樣累!【解析】as...as...和......一樣......9.For one week , she did not do any housework and neither did I.一周的時間,她不做任何家務(wù),我也不做。
【解析】neither +助動詞/系動詞/情態(tài)動詞 +主語 “某人(主語)也不” ⑴ neither兩者都不
neither …nor… 既不…也不…,連接兩個詞做主語,謂語動詞由后一個主語確定 Neither Tom nor Jim is a student ⑵ 表達(dá)“…也不……” 則用 “Neither /Nor + be / V助 / V情 + 主”
—The first one wasn’t bad.— Neither was the second.第一個并不壞。-第二個也不是。10.The next day , my mom came home from work to find the house clean and tidy.第二天,媽媽下班回到家后發(fā)現(xiàn)房間很干凈、整潔?!窘馕觥縡ind +賓語+賓語補(bǔ)足語 【注】find → found →found v尋找
(1)find sb.doing sth 發(fā)現(xiàn)某人做某事
(2)find it + adj.+ to do sth 發(fā)現(xiàn)做某事很……
◆find it difficult/ hard to do sth 發(fā)現(xiàn)做某事很困難 She found _it__ hard to finish the work by herself.她發(fā)現(xiàn)自己很難完成這項工作。
11.She asked in surprise.她吃驚地問道?!窘馕觥縤n surprise 驚奇地;吃驚地
surprise v 使吃驚→surprising adj.令人吃驚的 →surprised adj.吃驚的
to one’s surprise 使某人吃驚的是 in surprise 吃驚地 be surprised at 對……感到吃驚 To my surprise_(使我吃驚的是),he got the first prize in the exam.12.“ I’m so sorry, Mom.I finish understand that we need to share the housework to have a clean and comfortable home.” I replied.“對不起,媽媽。我終于理解為了擁有一個干凈、舒適的家我們需要共同來分擔(dān)家務(wù)。” 我回答說。
【解析1】need v 需要 用于肯定句,是實義動詞。
(1)人做主語,sb.need to do sth 某人需要做某事(2)物做主語,sth need doing sth= sth need to be done ①Students need ___to have_(have)a good rest in studying.②The watch needs__mending___(mend).手表需要修。用于否定句或疑問句,是情態(tài)動詞(1)needn’t = don’t have to 沒有必要
(2)need ,must 引導(dǎo)的一般疑問句,肯定會的用must,否定回答用needn’t
— Must I go there now? — Yes,you must/No, you needn’t
【解析2】share 分享;共用 share sth 分享或共用某物 share sth with sb.與某人分享某物(All his friends __Shared___ his happiness when he won the match.13.Could I hang out with my friends after the movie? 看完電影后我能和朋友們一起閑逛嗎?
【解析】hang out 閑逛 hang up 把......懸掛/掛起 14.Could you please pass me the salt?你能把鹽遞給我嗎?
【解析】pass ⑴v 給;遞;走過;通過 pass sb.sth 把某物遞給某 Pass on 傳遞 Please pass the paper on to the other students.⑵ v 通過;路過 I pass your home.⑶ v 通過(考試);及格 Tom can pass his math exam.15.Could I borrow that book?我能借下你那本書看嗎、Could you lend me some money?你能借我一些錢嗎? 【解析】borrow /lend/keep(1)borrow 借入 ,與from 連用,尤指主語“【借進(jìn)來”】
borrow sth from sb.從某人那里借某物 You can borrow the book from the library.(2)lend 借出 ,與to 搭配 【指借出去】
lend sb sth=lend sth to sb 把某物借給某人He doesn’t want to lend his book to others.(3)keep 保留,保存(延續(xù)動詞,可以與表示一段時間的狀語連用)【指借一段時間】 【記】 I want to _borrow__ a bike from my friend but he didn’t _lend___ it to me, because Tom had _kept____ it for two days.16.I cut my finger and I’m trying not to get it wet.我的手指割傷了,傷口不能弄濕。
【解析】try(not)to do sth努力(不)做某事。try v 試圖,設(shè)法,努力 【拓展】(1)try on 試穿
(2)try to do sth 努力做某事 【側(cè)重盡力做】
(3)try doing sth 試圖做某事 【側(cè)重嘗試做】
(4)try one’s best to do sth= do one’s best to do sth 盡某人最大努力做某事 17.I hate to do chores.我討厭做家務(wù)。
hate to do sth 討厭做某事, 表示某次具體行為或動作。I hate to trouble him.我討厭麻煩他 hate doing sth不愿意做某事 表示經(jīng)?;蛄?xí)慣性行為或動作。She hates smoking in her room.她討厭在房間里抽煙。
18.Could I ask you to help me with some chores then? 那我能請求你幫我做些雜活嗎?
【解析】ask sb.to do sth 要求某人做某事。
ask for 請求,要某物
ask sb.about sth 向某人詢問關(guān)于某事(1)ask sb.for help 向某人請求幫助(2)ask sb.(not)to do sth請求某人做某事 ask構(gòu)成的短語: 短語 含義
ask sb.to do sth 請某人做某事 ask sb.not to do sth 不讓某人做某事 ask sb for sth 向某人要某物 ask for help 尋求幫助
19.I’ll finish my homework while you help me with the dishes.當(dāng)你幫我洗盤子的時候,我將完成我的家庭作業(yè)。
【解析1】finish doing sth 完成某事
— Can you finish _reading__ these books before 10 o’clock? 你能在十點前讀完這些書嗎? — Yes, I can.【解析2】while conj.“在……期間; 當(dāng)……的時候” While 引導(dǎo)的時間狀語從句的謂語動詞只能是延續(xù)動詞。
_While __ the children have fun, parents can take dance lessons on the beach.當(dāng)孩子們玩得開心時,父母可以在海灘上上舞蹈課。【解析3】help sb.with sth.在某事上幫助某人。【注】help v 幫助 → helpful adj.有幫助的
(1)help sb.do sth.=help sb.with sth.幫助某人做某事(2)with the help of sb.=with one’s help在某人的幫助之下(3)without the help of 沒有在…的幫助之下 ①I think reading is very __helpful____(help).② __Without____ your help, we couldn’t catch the thief.抓住小偷。20.Could I invite my friends to a party? 我能邀請我的朋友們來聚會嗎? 【解析】invite sb.to Sp.邀請某人去某地 【解析】invite v → invitation n邀請(1)invite sb.to do sth 邀請某人做某事(2)invite sb.to +地點 邀請某人去某地
21.I don’t understand why some parents make their kids help with housework and chores at home.我不理解為什么有些父母在家讓孩子們幫忙做家務(wù)和雜務(wù)。【解析】make sb.do sth 讓某人做某事 make → made →made v.做,制作,使得
(1)make sb/sth + 形容詞 “讓某人或某物…” make you happy(2)make sb/sth do sth 使某人做某事 make me laugh.Colors can change our moods and make us _feel__ happy or sad, energetic or sleep.顏色可以改變我們的心情,使我們感到高興或悲傷,精力充沛或睡眠。22.They don’t have time to study and do housework,too.他們也沒有時間來學(xué)習(xí)家務(wù)和做家務(wù)?!窘馕觥縣ave time to do sth.有時間做某事 have time =be free 有空
23.Housework is a waste of their time.做家務(wù)是在浪費(fèi)他們的時間。
【解析】a waste of 浪費(fèi) a waste of time 浪費(fèi)時間 a waste of money 浪費(fèi)金錢 waste v “浪費(fèi)”
waste time/money on sth waste time / money(in)doing sth 在做某事上花費(fèi)時間/金錢 Don’t _waste_water.Can’t you see the sign “save water”?不要浪費(fèi)水。你看不到“節(jié)約用水”的牌子嗎? 24.They should spend their time on schoolwork in order to get good grades and get into a good university.為了取得好成績并考上一所好大學(xué),他們應(yīng)該把時間用在學(xué)習(xí)上。【解析1】spend...on sth 在某事上花費(fèi)......spend/pay/cost/take 花費(fèi)
(1)spend→spent→spent v 花費(fèi),主語是人
◆ sb.+ spend +時間/錢+on sth ◆sb.+spend +時間/錢+(in)doing sth ◆spend on= pay for 支付
He spends too much time on the computer games.他花太多時間在電腦游戲上。
Remember to spend some time _with_ your loved ones, because they’re not going to be around forever.記得花些時間和你所愛的人在一起,因為他們不會永遠(yuǎn)在你身邊。My father _spent_ one hundred thousand yuan on his new car.我父親花了十萬元買他的新車
(2)pay →paid →paid v 支付,主語是人
◆sb.+ pay + 錢+for sth I pay 10 yuan for the book.— How much did you pay for this computer? 你花了多少錢買這臺電腦 — Five hundred dollars.(3)cost→ cost→ cost v 花費(fèi),主語是某物或某事
◆sth cost sb.+錢 某物花費(fèi)某人多少錢 A new computer costs me a lot of money.I bought a new sweater last weekend.It ___cost_ me 120 yuan.上周末我買了一件新毛衣。我花了120元
(4)take→took → taken v 花費(fèi)
◆It takes /took sb.some time to do sth.做某事花費(fèi)某人多長時間 It takes him 3 hours to do his homework.他花了3個小時做作業(yè)。
【解析2】in order to “目的是;為了” 后接動詞原形。in order to do sth 為了做某事 He ran quickly in order not __to be___ late for the meeting.他跑得很快,為了不遲到?!窘馕?】get into =enter 進(jìn)入 【拓展】與get相關(guān)的短語:
get up 起床 get back 返回 get over 克服
get dressed穿衣 get into進(jìn)入 get/be lost丟失 get off/on下/上車 get on well with sb.與某人相處得好 get out of從…出來 get warm 變曖 get ready for +n.為…做準(zhǔn)備 get ready to do sth.準(zhǔn)備做某事 get well康復(fù) get a chance 有機(jī)會、得到機(jī)會
get/go to sleep(fall asleep)入睡 相關(guān):(be asleep睡著)25.Also,when they get older, they will have to do housrwork so there’s no need for them to do it now.而且,當(dāng)他們長大的時候,他們也將會做家務(wù),因此,他們沒必要現(xiàn)在在做。【解析】get older 長大 get/ become/ go辨析:
⑴ get+adj較多地與形容詞比較級連用。The days are getting longer and longer.天變得越來越長
⑵ become 強(qiáng)調(diào)變化的結(jié)果 It's becoming colder and colder.天氣變得越來越冷。⑶go+adj.''表示令人不快的事情 go bad變壞,go blind變瞎,go hungry挨餓
26.It is the parents’ job to provide a clean and comfortable environment at home for their children.在家為孩子們提供一個干凈、舒適的環(huán)境是父母的義務(wù)?!窘馕觥縫rovide sth.for sb.為某人提供某物 provide v 提供
provide sb.with sth.(sb 前介詞用for)=provide sth for sb.(sth 前需加介詞with)供應(yīng)某人某物
相當(dāng)于:offer sb.sth.= offer sth to sb.provide 為應(yīng)急等做好準(zhǔn)備而“提供; 供給” provide sb.with sth.=provide sth for sb.提供某人某物
offer 側(cè)重表示“愿意給予” offer sb.sth.= offer sth to sb.對某人提供某物 offer to do sth 主動提出干某事
supply 定期“供應(yīng)” , 強(qiáng)調(diào)替代或補(bǔ)充所需物品 Supply sb.with sth=supply sth.to sb.為某人提供某物
①The Internet provides us _with__a lot of _information___we need.因特網(wǎng)給我們提供了許多我們需要的信息。
② —Could you please provide us _with___ some information about the students’ health? — Of course, it’s my pleasure.你能為我們提供一些關(guān)于學(xué)生的健康信息?當(dāng)然,這是我的榮幸。
27.And anyway, I think doing chores is not so difficult.無論如何,我認(rèn)為做家務(wù)并不那么難。
【解析】anyway 無論如何,(一般放在句首,用逗號和句子隔開)
28.I think it is important for children to learn how to do chores and help their parents with housework.我認(rèn)為對孩子們來說,學(xué)習(xí)如何做雜務(wù)并幫助他們的父母做家務(wù)是很重要的。【解析】It is important for sb.to do sth.對某人來說做某事是重要的
29.Children these days depend on their parents too much.現(xiàn)在的孩子太依賴他們的父母。
【解析】depend on 依靠;信賴
—— Shall we go for a picnic tomorrow? —— Well, it all ___depends on____ the weather.30....Everyone should do their part in keeping it clean and tidy.每個人都有責(zé)任保持家里的干凈和整潔。
【解析1】 do one’s part 盡職責(zé);盡本分 Do one’s part in doing sth 在做某事上盡職責(zé) 【解析2】keep +sth /sb.+adj.“使......處于某種狀態(tài)”
Her mother asked her to keep the windows __open__ and the door __closed__.她媽媽叫她把窗戶打開,關(guān)上了門
keep 系動詞 “保持” keep + adj.We must keep healthy.實義動詞 “保持;繼續(xù)”
(1)keep(on)doing sth 繼續(xù)做某事 He was in great pain but he kept on working He kept on __ talking__ after the ball rang for class.他不停地球響下課后說。(2)keep sb.Doing sth 讓某人一直做某事 I’m sorry to have kept you waiting for so long.My teacher kept me __doing___ homework all the afternoon.對不起,讓您久等了。我的老師讓我整個下午做作業(yè)。
31.Doing chores helps to develop children’s independence and teaches them how to look after themselves.做雜務(wù)不僅可以培養(yǎng)孩子們的獨立性還可以教 他們?nèi)绾握疹欁约??!窘馕觥縟evelop independence 培養(yǎng)獨立意識
develop v→development n 發(fā)展→developing adj.發(fā)展的→developed adj.發(fā)達(dá)的 a developing country 一個發(fā)展中國家a developed country 一個發(fā)達(dá)國家 China is a __developing___country.32.Since they live in one house with their parents, they should know that everyone should do their part in keeping it clean and tidy.既然他們和父母同住在一個房子里,他們應(yīng)該知道保持家里干凈、整潔每個人都應(yīng)該參與。
【解析】since conj.既然(表示對方已知的事實或理由,常放在句首)
.—You have been in Neijiang very long? —Yeah.__Since___my parents came here.你在內(nèi)江已經(jīng)有很長時間了嗎?-是的。因為我的父母來到這里。
33.Our neighbor’s son got into a good college but during his first year, he had n idea how to take care of himself.我們鄰居的兒子上一所好大學(xué),但是在第一年的時候,他還不知道如何照顧自己。
take care of 照顧Thanks for your invitation, but I’m so sorry I can’t go.I need to ___take care of___ my baby at home.【拓展】與take相關(guān)的短語:
take photos/pictures 照像 take away拿走 take out取出(work out算出)take care當(dāng)心 take a walk散步
take medicine服藥 take place發(fā)生take one’s temperature量體溫
take one’s time別著急
34.As a result , he often fell ill and his grades dropped.結(jié)果,他常常生病,功課也落下了。
【解析1】as a result 結(jié)果(插入語,放在句首,用逗號隔開)
Don’t ask him too late into the night, __As a result___ , he is only a small child.不要太深夜問他,作為一個結(jié)果,他只是一個小孩?!窘馕?】fall ill 生病 fall asleep 入睡
35.The earlier kids learn to be independent , the better it is for their future.孩子們越早學(xué)會獨立,對他們的未來越好。
【解析】the + 比較級,the + 比較級 “越......越......”
The more you smile, the happieryou will feel.你笑得越多,你就會感覺到快樂。
第三篇:英語八年級下冊第三單元知識點總結(jié)
Unit 3.Could you please clean your room?
一、短語動詞
1、take out 帶出去;取出;拔出;除掉 動副詞組
代詞作賓語時必須放在兩詞之間。
2、come over 固定短語
過來,順便來訪,拜訪。后面加介詞to,后接表示地點的名詞作賓語。拓展:take out of 把---從---取出/帶出
3、hang →hung→hung
hang out 閑逛;溜達(dá)。
4、throw down扔下;隨手丟下
其中throw可用作及物或不及物動詞,意為扔,擲→threw→thrown 拓展:throw at向----扔去(帶有攻擊性)throw to 扔給---(不含惡意)throw away扔掉 SectionB
1、take care of 照顧;照料。相當(dāng)于 look after后可接名詞、(反身)代詞作賓語。Take good care of相當(dāng)于look after well
2、二、動詞用法
1、finish 及物動詞 完成后跟名詞、代詞或動詞ing形式作賓語。拓展:與finish一樣用法的動詞或動詞短語有:enjoy/look forward to/mind/have fun/practice/be busy/consider/feel like/give up
2、pass用作及物動詞
給;遞; pass sb sth =pass sth to sb把某物遞給某人。
走過、通過(考試等)
作不及物動詞,(時間)過去,流逝
3、borrow sth from sb向某人借某物。
非延續(xù)性動詞
Lend(lent;lent)sb sth=lend sth to sb借給某人某物。非延續(xù)性動詞
Keep 由“保存”引申為“借”,延續(xù)性動詞,可與時間段連用。四川-----Excuse me,can I_____your pen?-----sorry,I have_____it to Bob.A.borrow;lend B.borrow;borrowed C.lend;borrowed D.lend;lent
4、hate及物動詞
厭惡;討厭,表示一種感情或心理狀態(tài),不能用于進(jìn)行時態(tài)。
Hate sb/sth不喜歡某人或某物
Hate to do/doing sth 厭惡做某事(某一次或經(jīng)常性的)相當(dāng)于like的用法。
SectionB
1、invite及物動詞
邀請
名詞invitation 邀請;請?zhí)?/p>
Invite sb to +地點名詞。邀請某人到某地。
Invite sb to do sth 邀請某人做某事。
2、make sb do sth 讓某人做某事。
3、動詞辨析:
單詞
主語
常用結(jié)構(gòu)
含義 Spend(spent)
人
sb spend time/money on sth
Sb spend time/money doing sth Pay(paid)
人
sb pay money for sth Cost(cost)
物
sth cost sb some money Take(took)
it作形式主語 it takes sb some time to do sth 四川:-----I_________a lot of time palying computer games everyday.----oh,boy.it’s bad for your eyes.A.spend B.takes C.pay
4、provide sth for sb =provide sb with sth給某人提供某物
Offer sb sth =offer sth to sb主動給某人提供某物
Offer to do sth 主動提出做某事。
5、depend on依靠;依賴 independent獨立的 independence獨立性
6、develop作及物動詞或不及物動詞
發(fā)展;壯大。Development發(fā)展。
Developed/developing 前者是發(fā)達(dá)的后者是發(fā)展中的。
7、Have no idea 相當(dāng)于don't know
不知道、drop(dropped)→dropping
(1)drop意為“丟失或落下”時,既可以作及物動詞,也可以作不及物動詞。如:
She was scared and dropped the cup.她嚇壞了,丟落了茶杯。
The glass dropped from her hand.玻璃從她的手中掉了下來。
(2)drop作動詞還有“(價格)下降;放棄”的意思,如:
The price of the rice has dropped.大米的價格已經(jīng)降下來了。
Don't drop math.別放棄數(shù)學(xué)。
(3)drop也可作名詞,表示“滴”,如:
A drop of rain fell on my face.一滴雨落在我的臉上。
(4)drop還可指“下跌;落下的距離”,如:
There was a sudden drop in the temperature yesterday.昨天氣溫大幅下降。
拓展:drop behind 落后 drop in/by偶然拜訪
eye drops 眼藥水 a drop in the ocean滄海一粟
Drop out of school輟學(xué)
三、名詞
1、rubbish 不可數(shù)名詞
垃圾,廢棄物
2、mess名詞
雜亂;不整潔。常用短語:in a mess 亂七八糟
3、chores
家務(wù)
可數(shù)名詞
Housework(homework)家務(wù)
不可數(shù)名詞 SectionB
1、stress不可數(shù)名詞,精神壓力;心理負(fù)擔(dān)。
Under the stress of 在---壓力之下。
2、waste 名詞
浪費(fèi)
a waste of time 浪費(fèi)時間
不可數(shù)名詞
廢物;垃圾;浪費(fèi)
作形容詞
無用的;廢棄的;丟棄的。
作及物動詞
浪費(fèi)
四、形容詞
五、副詞
SectionB
1、anyway 副詞
而且;加之。
The coat is too expensive and anyway I don’t like the color.還可意為“不管怎樣,無論如何,即使這樣。
Anyway ,it’s worth trying.The water was cold but he took a shower anyway.六、介詞短語
1、in front of在---面前;是指在一定范圍外。
in the front of 在----前部,是指在一定范圍內(nèi)。廣東中考----why are you standing,Alice?-----I can’t see the blackboard clearly.two tall boys are sitting_________me.A.behind B.next to C.between D.in front of
2、in surprise 驚訝地;驚奇地,常用作狀語。
拓展:to one’s surprise 使某人吃驚的是,常放在句首,作狀語。
sectionB
1、in order to目的是;為了 后接動詞原形,引導(dǎo)目的狀語。位置可放在句首,也可放在句中。否定為:in order not to do.In order that 后面接從句,表示目的,從句中常含有情態(tài)動詞。廣東:in order _______for the meeting,my sister forced herself to get up early this morning.A.not to be late B.not being late C.to be late D.being late
3、as a result 結(jié)果;因此
拓展:as a result of 由于----;作為------的結(jié)果。
七、連詞
1、the minute意為“一----就----”引導(dǎo)時間狀語從句,其后省略了引導(dǎo)詞that相當(dāng)于the moment或as soon as(通常情況下主從句時態(tài)要一致。但若主句用一般將來時,從句則要用一般現(xiàn)在時表將來。)哈爾濱:boys and girls,calm down and focus on the test paper____you begin to think about the answers.Be confident.you can do it.A.as if B.as soon as C.although
2、?when是at or during the time that, 既指時間點,也可指一段時間; while是during the time that,只指一段時間,因此when引導(dǎo)的時間狀語從句中的動詞可以是終止性動詞,也可以是延續(xù)性動詞,而while從句中的動詞必須是延續(xù)性動詞。
②when 說明從句的動作和主句的動作可以是同時,也可以是先后發(fā)生;while 則強(qiáng)調(diào)主句的動作在從句動作的發(fā)生的過程中或主從句兩個動作同時發(fā)生。
③由when引導(dǎo)的時間狀語從句,主句用過去進(jìn)行時,從句應(yīng)用一般過去時;如果從句和主句的動作同時發(fā)生,兩句都用過去進(jìn)行時的時候,多用while引導(dǎo),如: a.When the teacher came in, we were talking.當(dāng)此句改變主從句的位置時,則為:
While we were talking, the teacher came in.b.They were singing while we were dancing.SectionB
1、since 由于;因為;既然,引導(dǎo)原因狀語從句,通常放在句首。
還可引導(dǎo)時間狀語從句,自---以來。一般用在完成時當(dāng)中。
八、特殊句型
1、as---as---與---一樣,用于同級比較。第一個as為副詞,后跟形容詞或副詞的原級;第二個為連詞,引導(dǎo)比較狀語從句。
否定形式:not as/so---as---,不如----
2、neither+連系動詞be/助動詞/情態(tài)動詞+主語
----也不。
這是一個倒裝句,表示上句否定的情況也同樣適合后者。
So+連系動詞be/助動詞/情態(tài)動詞+主語
----也是。
這是一個倒裝句,表示上句肯定的情況也同樣適合后者。
拓展:neither+主語+連系動詞be/助動詞/情態(tài)動詞
----的確不是這樣。(表示說話者同意上文中說話者的否定觀點。)
So+主語+連系動詞be/助動詞/情態(tài)動詞
-----的確是這樣。
表示說話者同意上述說話者說出的觀點。
福建----last night I didn't watch the TV show。A Bite of China 2
-----_______did I.I was preparing for today’s test then.A.So B.Either C.Neither SectionB
1、do one’s part in(doing)sth 盡某人的職責(zé)做某事。
2、The+比較級,the+比較級
表示越----,就越-----
比較級+比較級
表示越來越------貴州:__________children there are in a family,________their life will be.A.the less;the better B.The fewer;the better C.Fewer;richer D.More;poorer
九、語法專項 1.can 的用法:
(1).表示能力、許可、可能性。表示能力時一般譯為“能、會”,即有種能力,尤其是生來具備的能力,此時may 和must 均不可代替它。如:She can swim fast, but I can’t.她能游得很快,但我不能。I can see with my eyes.我用眼睛看。
(2).表示許可,常在口語中。如:You can use my dictionary.你可以用我的字典。
(3).表示推測,意為“可能”,常用于否定句和疑問句中,此時can’t 譯為“ 不可能”?!狢an it be our teacher?那個人有可能是我們老師嗎?—No, it can’t be our teacher.He is on a visit to the Great Wall.不可能。咱們老師正在游覽長城呢。2.could的用法:
(1).can的過去式,意為“ 能、會”,表示過去的能力。如:He could write poems when he was 10.他十歲時就會寫詩。
(2).could在疑問句中,表示委婉的語氣,此時 could 沒有過去式的意思。如:Could you do me a favour? 你能幫我個忙嗎?—Could I use your pen? 我能用一下你的鋼筆嗎? —Yes, you can.可以。(注意回答)
?—________ you pass me a pen? I’d like to write down the phone number.—Sure.Here it is.A.Can B.Need C.Might D.Must ?The man in the office___be Mr.Black, because he went home just now.A.mustn’t B.may not C.can’t D.needn’t —___ I take the newspaper away? —No, you mustn't.You____read it only here.A.Must;can B.May;can C.Need;must D.Must;must
第四篇:新人教八年級下冊英語unit8知識點及練習(xí)題
新人教版八年級英語(下)Unit8單元知識講解及練習(xí)
Unit8 Have you read Treasure Island yet?知識點撥
一、重點短語
1.on page 25 在第2 5 頁 2.the back of the book 書的背面 3.h u rry up 趕快;匆忙 4.in tw o weeks 在兩周之內(nèi) 5.go out to sea 出海
6.an island fu ll of treasures 一個滿是寶藏的島嶼 7.w rite about 寫作關(guān)于??的內(nèi)容 8.finish doing sth.做完某事
9.w ait for another ship 等待另一艘船到來 10.learn to do sth.學(xué)會做某事
11.grow fru its and vegetables 種水果和蔬菜 12.a few weeks ago 幾個星期前
13.the m arks of another m an’ s feet 另一個人的腳印
14.not long after that 不久之后 15.run towards sp.跑向某地
16.use...to do sth.用??來做某事 17.signs le ft behind by someone 某人留下的標(biāo)記
18.read the newspaper 看報 19.science fiction 科幻小說
20.can’ t w ait to do sth.迫不及待地做某事 21.a good way to wake up 醒來的一個好辦法 22.number of people 人數(shù)
23.used to do sth.(過去)常常做某事 24.study abroad 在國外學(xué)習(xí)25.make sb.do sth.使某人做某事 26.come to realize 開始意識到 27.ever since then 自從那時起 28.the southern states of America 美國的南部地區(qū) 29.belong to 屬于
30.be kind to each other 善待彼此 31.tru s t one another 互相信任 32.the beauty of nature 大自然的美 33.have been to sp.去過某地
34.do some research on sth.對??做研究 35.hope to do sth.希望做某事 36.see sb.do sth.看到某人做某事
37.the firs t line in the song歌曲的第一行 38.enjoy success in享受??的成功 39.at the end of the day傍晚的時候
二、重點句型 1.Have you.?.yet?
— Have you read l ittle Women yet? 你讀過《小婦人》嗎?
— Yes,I have./N o , I haven’ t.是的,我讀過。/ 不,我沒有。2.Has...yet? — Has T in a read Treasure Island yet? 蒂娜讀過《金銀島》這本書嗎?
— Yes, she has.She thinks i t ’ s fantastic.是的,她讀過。她覺得它很棒。3.W ould you lik e...? W ould you like something to drink? 你要來點喝的嗎? 4.I heard...I heard you lost your key.我聽說你丟鑰匙了。
5....came to realize how m uch...She came to realize how much she actually missed all of them.她開始意識到,事實上她是多么想念他們所有的人。
練習(xí)題
一.單項填空。
()1.— Bill hasn’t finished reading Treasure Island yet.What about you? — I’ve read it twice.A.just then B.just now C.yet D.already()2.Mr.Wang isn’t here.I think he _______ Guiyang.A.has gone to B.has been to C.goes D.went()3.Nobody told us _________.A.what to do it B.how to do C.where to do D.when to do it()4.—Have you ever been to Shanghai? —Yes, I ______ there last year.A.went B.have been C.have gone D.has been()5.—Where is your father? —He _____ Australia and he _______ Sydney for two weeks.A.has been to;has been in B.has gone to;has been in C.has been in;has been to D.has gone to;has been to()6.He took up my cell phone and made a long distance call as if the phone _____him A.belonged to B.was belonging to C.was belonged to D.had been belonged to()7.— Could you please water the flowers in the garden? — Oh, I A.have no time B.haven’t watered them C.have watered them D.can do it tomorrow(books students.A.borrows;from B.lends;to C.returns;to D.sells;to()9.I my lost wallet everywhere but I couldn’t it.A.looked for;find B.looked for , finding C.have found;look D.have found;looking()10.Amy ________ the windows already, so the room looks much brighter.A.cleans B.cleaned C.is cleaning D.has cleaned 二.閱讀理解
A One day, a fisherman caught a golden fish.“People let me go,” the golden fish said.“I will give you whatever you want.”
“Thank you, but I don’t want anything,” the fisherman said.He put the golden fish back into the sea.But the fisherman’s wife was angry.“You should ask for a bigger wooden basin!” she shouted.The fisherman went to the seaside and told the golden fish.“Don’t worry, she has a new basin now,” the golden fish said.The fisherman went home.But the wife was even angrier.“I want a large house!” The fisherman went to tell the golden fish again.But the old woman was never satisfied.“I want to be the queen of the sea!And I want the golden fish to serve me!”
The fisherman went to tell the golden fish.The golden fish swam away without saying anything.The fisherman walked back.His wife was in her cold clothes.Her old and broken wooden basin was next to her.根據(jù)短文內(nèi)容,判斷下列各句正誤。正確的在題號前括號內(nèi)寫“T”,錯誤的寫“F”。11.The fisherman caught the golden fish three times.12.The fisherman freed the golden fish after he caught it.13.The fisherman’s wife was really happy every time when her husband came back.14.The fisherman’s wife got a new basin, a large house and became the queen of the sea at last.15.The golden fish didn’t say a word but to swim away in the bed.文章大意:本文是一個寓言故事,講了一個貪得無厭,最終以無所獲得故事。11.F【解析】整體理解題 從文中可知漁夫并沒有捉住金魚三次。12.T 【解析】細(xì)節(jié)理解題。從第二段的““Thank you, but I don’t want anything,” the fisherman said.He put the golden fish back into the sea.”可知漁夫抓住金魚之后,就把它放了。
13.F 【解析】推理判斷題。漁夫的妻子每次都不滿意。
14.F 【解析】整體理解題 漁夫的妻子得到了一個澡盆和新房子,但沒有成為皇后。
15.T 【解析】細(xì)節(jié)理解題 從最后一段的“The golden fish swam away without saying anything.”可知答案。
三.書面表達(dá)
請你根據(jù)下表中所提供的信息以“Learn to express thanks”為題,用英語寫一篇演講稿。背 景 1.認(rèn)為上中學(xué)時吃好穿好是應(yīng)該的; 2.走向社會后沒有感恩意識。
學(xué)會感恩 1.感謝社會提供良好的教育機(jī)會; 2.感謝父母供養(yǎng)自己上學(xué); 3.感謝老師傳授知識;
4.感謝朋友的鼓勵與幫助。
參考詞匯:enter society 進(jìn)入社會,sense of thanks 感恩意識,behavior 行為 5.詞數(shù):80詞左右。開頭和結(jié)尾已給出,不計入總詞數(shù)。Good morning, boys and girls!The topic of my speech today is “Learn to express thanks”.In the future, we should never forget our society, parents, teachers and friends.At present, we should study harder to make our world more beautiful.Thank you for your listening
第五篇:新人教八年級下冊數(shù)學(xué)期末考試知識點歸納
新人教八年級下冊數(shù)學(xué)期末考試知識點歸
納
二次根式
知識回顧
1.二次根式:式子(ge;0)叫做二次根式。2.最簡二次根式:必須同時滿足下列條件:
⑴被開方數(shù)中不含開方開的盡的因數(shù)或因式;⑵被開方數(shù)中不含分母;⑶分母中不含根式。3.同類二次根式:
二次根式化成最簡二次根式后,若被開方數(shù)相同,則這幾個二次根式就是同類二次根式。4.二次根式的性質(zhì):(1)()2=(ge;0);(2)5.二次根式的運(yùn)算:
(1)因式的外移和內(nèi)移:如果被開方數(shù)中有的因式能夠開得盡方,那么,就可以用它的算術(shù)根代替而移到根號外面;如果被開方數(shù)是代數(shù)和的形式,那么先解因式,?變形為積的形式,再移因式到根號外面,反之也可以將根號外面的正因式平方后移到根號里面.(2)二次根式的加減法:先把二次根式化成最簡二次根式再合并同類二次根式.(3)二次根式的乘除法:二次根式相乘(除),將被開方數(shù)相乘(除),所得的積(商)仍作積(商)的被開方數(shù)并將運(yùn)算結(jié)果化為最簡二次根式.=(age;0,bge;0);(bge;0,agt;0).(4)有理數(shù)的加法交換律、結(jié)合律,乘法交換律及結(jié)合律,?乘法對加法的分配律以及多項式的乘法公式,都適用于二次根式的運(yùn)算.勾股定理1.勾股定理:如果直角三角形的兩直角邊長分別為a,b,斜邊長為c,那么a2+b2=c2。
2.勾股定理逆定理:如果三角形三邊長a,b,c滿足a2+b2=c2。,那么這個三角形是直角三角形。3.直角三角形的性質(zhì)
(1)、直角三角形的兩個銳角互余??杀硎救缦拢篴ng;C=90deg;ang;A+ang;B=90deg;(2)、在直角三角形中,30deg;角所對的直角邊等于斜邊的一半。ang;A=30deg;可表示如下:BC=AB ang;C=90deg;(3)、直角三角形斜邊上的中線等于斜邊的一半 ang;ACB=90deg;可表示如下:CD=AB=BD=AD D為AB的中點
4、直角三角形的判定
1、有一個角是直角的三角形是直角三角形。
2、如果三角形一邊上的中線等于這邊的一半,那么這個三角形是直角三角形。
3、勾股定理的逆定理:如果三角形的三邊長a,b,c有關(guān)系,那么這個三角形是直角三角形。
5、三角形中的中位線
連接三角形兩邊中點的線段叫做三角形的中位線。(1)三角形共有三條中位線,并且它們又重新構(gòu)成一個新的三角形。
(2)要會區(qū)別三角形中線與中位線。
三角形中位線定理:三角形的中位線平行于第三邊,并且等于它的一半。
四邊形
1.四邊形的內(nèi)角和與外角和定理:(1)四邊形的內(nèi)角和等于360deg;;(2)四邊形的外角和等于360deg;.2.多邊形的內(nèi)角和與外角和定理:(1)n邊形的內(nèi)角和等于(n-2)180deg;;(2)任意多邊形的外角和等于360deg;12.等腰梯形的判定:
(四邊形ABCD是等腰梯形
(3)∵ABCD是梯形且AD∥BC
∵AC=BD
there4;ABCD四邊形是等腰梯形 14.三角形中位線定理:
三角形的中位線平行第三邊,并且等于它的一半.15.梯形中位線定理:
梯形的中位線平行于兩底,并且等于兩底和的一半.一次函數(shù)
一、正比例函數(shù)與一次函數(shù)的概念:
一般地,形如y=kx(k為常數(shù),且kne;0)的函數(shù)叫做正比例函數(shù).其中k叫做比例系數(shù)。
一般地,形如y=kx+b(k,b為常數(shù),且kne;0)的函數(shù)叫做一次函數(shù).當(dāng)b=0時,y=kx+b即為y=kx,所以正比例函數(shù),是一次函數(shù)的特例.二、正比例函數(shù)的圖象與性質(zhì):
(1)圖象:正比例函數(shù)y=kx(k是常數(shù),kne;0))的圖象是經(jīng)過原點的一條直線,我們稱它為直線y=kx。
(2)性質(zhì):當(dāng)kgt;0時,直線y=kx經(jīng)過第三,一象限,從左向右上升,即隨著x的增大y也增大;當(dāng)k0,bgt;0圖像經(jīng)過一、二、三象限;(2)kgt;0,blt;0圖像經(jīng)過一、三、四象限;(3)kgt;0,b=0圖像經(jīng)過一、三象限;(4)klt;0,bgt;0圖像經(jīng)過一、二、四象限;(5)klt;0,blt;0圖像經(jīng)過二、三、四象限;(6)klt;0,b=0圖像經(jīng)過二、四象限。
一次函數(shù)表達(dá)式的確定
求一次函數(shù)y=kx+b(k、b是常數(shù),kne;0)時,需要由兩個點來確定;求正比例函數(shù)y=kx(kne;0)時,只需一個點即可.5.一次函數(shù)與二元一次方程組:
解方程組
從“數(shù)”的角度看,自變量(x)為何值時兩個函數(shù)的值相等.并
求出這個函數(shù)值
解方程組從“形”的角度看,確定兩直線交點的坐標(biāo).數(shù)據(jù)的分析
數(shù)據(jù)的代表:平均數(shù)、眾數(shù)、中位數(shù)、極差、方差
一元二次方程知識點總結(jié)
一、知識框架
二、知識點、概念總結(jié)
1.一元二次方程:方程兩邊都是整式,只含有一個未知數(shù)(一元),并且未知數(shù)的最高次數(shù)是2(二次)的方程,叫做一元二次方程。
2.一元二次方程有四個特點:(1)含有一個未知數(shù);(2)且未知數(shù)次數(shù)最高次數(shù)是2;(3)是整式方程。要判斷一個方程是否為一元二次方程,先看它是否為整式方程,若是,再對它進(jìn)行整理。如果能整理為ax2+bx+c=0(ane;0)的形式,則這個方程就為一元二次方程。
(4)將方程化為一般形式:ax2+bx+c=0時,應(yīng)滿足(ane;0)3.一元二次方程的一般形式:一般地,任何一個關(guān)于x的一元二次方程,經(jīng)過整理,?都能化成如下形式ax2+bx+c=0(ane;0)。
一個一元二次方程經(jīng)過整理化成ax2+bx+c=0(ane;0)后,其中ax2是二次項,a是二次項系數(shù);bx是一次項,b是一次項系數(shù);c是常數(shù)項。4.一元二次方程的解法(1)直接開平方法
利用平方根的定義直接開平方求一元二次方程的解的方法叫做直接開平方法。直接開平方法適用于解形如的一元二次方程。根據(jù)平方根的定義可知,是b的平方根,當(dāng)時,,當(dāng)b”、“=”、“l(fā)t;”)。
16.如圖,在四邊形ABCD中ABCD,若加上ADBC,則四邊形ABCD為平行四邊形?,F(xiàn)在請你添加一個適當(dāng)?shù)臈l件:,使得四邊形AECF為平行四邊形.(圖中不再添加點和線)轉(zhuǎn)眼之間一個學(xué)期也將過去了,同學(xué)們也迎來了期末考試,希望上文為大家提供的八年級下冊數(shù)學(xué)期末考試知識點歸納,能幫助到大家。
精編八年級數(shù)學(xué)下冊《全等三角形》知識點總結(jié) 2016學(xué)年初二下冊《反證法》知識點歸納:例題解析