上海版牛津英语8B-Unit3-知识点梳理.doc

八年级第二学期牛津英语知识点梳理及配套练习
Unit 3 Electricity
知识点梳理：
I 词组
1 one evening 一天晚上
2 get me a packet of electricity 给我带一包电
3 go out 出去
4 at last 最后
5 buy it in packets 一包包地买
6 look foolish 看上去很傻
7 flow through a wire 流过电线
8 measure the amount you use 测量你使用的电量
9 get a bill for 得到一张……的账单
10 in a way 在某种程度上
11 much more dangerous than … 比……危险得多
12 be careful with 小心对待
13 look like 看似……样
14 scratch one’s head 挠头
15 change … into … 把……变成……
16 think of 想一想；想出来
17 a light bulb 电灯泡
18 come from 来自于
19 different forms of energy 各种能量
20 be connected to 被连接到……
21 bury under the street 埋在路下
22 a power station 发电站
23 come back 回来
24 May I have … , please? 我可以……吗？
25 on his face 在他脸上
26 Here it is. 它在这儿
27 Didn’t you know that? 你不知道吗？
28 switch off 关上

II. 词性转换
1. dangerous (a.) 危险的 danger (n.) 危险
2. servant (n.) 仆人 serve (v.) 服务 service (n.) 服务
3. electricity (n.) 电 electric (a.) 电的 electrical (a.) 有关电的
4. foolish (a.) 愚蠢的 fool (n.) 傻瓜 /（v.）愚弄
5. monthly (ad.) 每月一次 month (n.) 月份
6. explanation (n.) 解释 explain (v.) 解释
7. careful (a.) 小心的 care (n. / v.) 关心 carefully (ad.) 小心地
careless (a.) 粗心的
8. invisible (a.) 看不见的 visible (a.) 看得见的
9. change (n. / v.) 变化 changeable (a.) 多变的
10. different (a.) 不同的 difference (n.) 不同点
11. power (n.) 力 powerful (a.) 强大的
12. politely (ad.) 有礼貌地 polite (a.) 有礼貌的 impolite (a.) 没礼貌的
13. contain (v.) 包含 container (n.) 容器
14. clear (a.) 清楚的 clearly (ad.) 清楚地

III. 语言点
1. I’m going to buy a packet of sweets.
a packet of 意为“一包；一袋”。
句中的sweets作名词，意为“糖果”；sweet也可作形容词，意为“甜的”。
2. I’ve tricked Daisy at last.
句中的trick作动词，意为“戏弄”；trick也可作名词，意为“诡计；花招；骗局”。如：play a trick on sb.。
at last意为“最终”，与in the end和finally意思相同。
3. She doesn’t even know what electricity is.
even在此作副词，表示“甚至；连；即使”，用来强调出乎意料。
even还可以用于比较级前，表示“甚至更；愈加；还”。如：even happier。
4. She’ll really look foolish.
句中的look为系动词，意为“显得”，后接形容词foolish作表语，说明主语的状态。
5. A meter measures the amount you use.
amount意为“数量，数额”。an amount of表示“一定量的”，一般修饰不可数名词，修饰可数名词则用a number of。
6. It’s like water, in a way.
in a way意为“在某种程度上；不完全地”，可用partly代替；如表示“就某些方面而言”则用in some ways。
7. “That’s not a bad explanation,” said Dad, “although electricity is much more dangerous than water.
句中although是连词，意为“虽然；尽管”，用以引导让步状语从句，可用though来代替，但不能与but同时出现在句子中。
although与though的区别：(a) although常用于较正式的场合。（b）even可以与though连用来加强语气，但不可以与although连用。（c）though可用于句末，而although则不可以。
句中much是副词，意为“……的多”，用来修饰形容词或副词的比较级。类似可修饰比较级的词还有：still, even, far, a little, a lot等。
8. You must always be careful with it.
be careful with意为“小心对待；谨慎处理”，后常接名词或代词。
Be careful也可以单独使用，意为“小心”，用以提醒他人注意即将来临的危险。
如要接句子，则使用be careful (that) …。
9. Can you tell me what it looks like?
look like意为“看似……样”，look在此处是系动词，like为介词。此外，look like常和what连用表示“看起来怎么样？”
10. Dad said, “Nobody’s ever seen electricity.”
句中Nobody’s是Nobody has的缩写，与后面的seen构成现在完成时。
11. Can you think of an example?
句中think of意为“想一想；想出来”。think of也可以表示“考虑；关心”，此时与think about意思相同。如：We are thinking of / about going to France。
另外，What do you think of …?意为“你认为……怎么样？”，可用How do you like …?代替。
11. Well, it comes into our flat through thin wires, and these are connected to thick wires that are buried under the street.
句中connect是动词，意为“连接；联合”，与join或link意思相近。
一般connect … with … 指“……和……连接”，而connect … to … 指“把……连接到……”。be connected to是个被动结构，表示“被连接到……”的意思。
12. They’re packets that contain electricity.
句中that引导的从句是定语从句，用来修饰之前的名词，此处that还可以用which代替。
13. Didn’t you know that，Benny?
这是一个反问句。在回答反问句时，与反意疑问句相似。表示知道时，应用Yes, I do.；表示不知道时，应用No, I don’t.。

IV. 语法
情态动词
一、主要特征。
情态动词后的动词都用原形。构成疑问句，通常把情态动词放在主语前；构成否定句，not放在情态动词之后，其缩写形式为can’t, mustn’t, needn’t, shouldn’t等。
二、主要用法。
1. 用can, could和be able to表示能力。
(1) can意为“能够”，否定形式为cannot或can’t。
如：He can speak five foreign languages.
(2) could是can的过去式。因此，对于过去的时间（如yesterday, last week等），我们不用can或can’t，而用could和couldn’t。
如：When I was young, I could run very fast.
(3) be able to一般可以代替can，也可以表示能力。但can只有一般现在时和一般过去时(could）,而be able to则有更多的时态形式。
如：My little brother has been able to write.
2. 用must与mustn’t, have to与don’t have to, needn’t表示义务。
(1) must用以表示“必须做某事”或“一定要做某事”，具有强制性，表示一定的责任或义务。
如：The windows are very dirty. I must clean them.
(2) mustn’t是must的否定形式，表示“禁止绝不允许”，具有强制性。
如：You mustn’t play football in the street.
(3) must没有过去时，要表达过去的含义，我们可使用had to代替must。
此外，have to侧重这种“义务”或“责任”源于某种客观情况或规定，并非说话者本人能够控制。
如：We missed the last bus, so we had to walk home.
(4) don’t have to与needn’t是“不必”的意思，没有强制性。两者意思相近，但在使用时，前者有人称、时态的变化；后者没有人称变化，而且一般表示现在时间的含义。

如：It has just rained, so he doesn’t have to water the garden.
You needn’t swim in the sea. We have a swimming pool in our hotel.
(5) must用于一般疑问句中，其肯定和否定回答应引起注意。
如：Must we go now? 我们一定要走吗？
- Yes, we must. 是的，我们一定要走。
- No, we mustn’t. 不，我们不可以走。
Must I finish the work this week? 我一定要在这星期完成这项工作吗？
- Yes, you must. 是的，你一定要完成。
- No, you needn’t. 不，你不一定要完成。
从以上例子中可以看出，用must提问的一般疑问句，否定回答并不一定是mustn’t。根据实际含义和情况，我们需要正确选用mustn’t或needn’t来回答。
3. 用can, could与may表示“许可”。
(1) 在请求对方的许可，或是准许你做某事时，常用情态动词can, could和may。can最为常用；could较为婉转，更有礼貌；may则比较正式。
如：Can I open the window? - Yes, you can. / No, you can’t.
Could I borrow a pencil, please? -Yes, certainly. / No, I’m afraid not.
May I leave early today? - Yes, you may. / No, you may not.
(2) 表示给予许可时，通常用can或may，而不用could。
如：Could I borrow a pencil? - Of course you can.
May I sit here? - No, you may not.
4. 用can, could与would表示“请求”。
当我们需要别人的帮助时，常使用can, could和would这三个情态动词进行提问，但在回答时，could和would则很少使用。
如：Can you open the window? - Yes, I can.
Could you pass me the salt, please? - Yes, certainly.
Would you help me carry my suitcase? - No, I’m afraid not.
常见的肯定回答：Of course I can. / OK. / All right.
常见的否定回答：I’m afraid I can’t / Of course not.
5. 用must和can’t表示“猜测”。
1) must表示说话者对某事的发生或情况很有把握，意为“肯定；一定”。
如：Her flat is very near Xujiahui. It must be very noisy.
(2) can’t表示说话者有相当的把握确定某事不会发生，意为“不可能”。
如：You’ve just had lunch. You can’t be hungry.
6. 用should和ought to表示“义务”和“建议”。
(1) should和ought to表示应该做某事，或做某事的动机是正确的。一般可以相互替换。
如：You should / ought to put your rubbish in the bin.
(2) ought to的否定形式为ought not to或oughtn’t to。构成疑问句，把ought提前至主语前。
如：You ought not to watch TV for too long.
Ought we to discuss the work now?
(3) should和ought to用在疑问句中时，常用来询问他人的见解或建议。
如：Ought I to finish my homework now?
- Yes, you ought to.
(4) should和must的区别在于：前者多用于劝说他人的错误行为或给予他人一些建议，不具备强制性；而后者意为“必须”，用于规定或约束他人的行为，具有强制性。
如：You shouldn’t be cruel to animals.
You mustn’t park you car here. Drive it away immediately.
(5) should和ought to常与动词think连用。
如：I think Carol should buy some new clothes.
It’s late. I think I ought to go home now.
宾语从句
一、概念。
在句中用作宾语的从句叫做宾语从句。宾语从句可分为三类：动词的宾语从句，介词的宾语从句和形容词的宾语从句。
二、语序。
宾语从句的构成为“引导词 + 主语 + 谓语 + 其他”，其语序是陈述句语序。
三、引导词。
1. 如从句是陈述句，用连接词that引导（that在口语或非正式文体中常省略）。
如：We know (that) there are two kinds of sports.
2. 如从句是特殊提问句，用连接副词why, when, where, how或连接代词who(m), what, which引导。
如：Do you know why I like team sports?
I don’t know how they got the tickets.
3. 如从句是一般疑问句，用连接词whether或if引导（口语中常用if）。if和whether意为“是否”。
如；I don’t know whether / if they have decided on the date of the meeting.
4. 如从句是选择疑问句，多用连接词whether引导，特别是与or not连用时。
如：I don’t know whether they will come for our help or not.
四、时态。
1. 如果主句是现在的时态，从句的时态可根据实际情况而定。
如：I tell him that I moved to Beijing last year.
I have heard that he will come back next week.
2. 如果主句是过去的某种时态，那么从句的时态也要用过去的某种时态。
如：He said that there were no classes yesterday.
Tom told me that he would have a birthday party.
3. 如果宾语从句表述的是客观真理、自然现象等时，不管主句是什么时态，从句都要用一般现在时。
如：The teacher said that light travels much faster than sound.
五、从句的简化。
1. 当主句谓语动词是find, see, watch, hear等感官动词时，从句可简化为“宾语+宾补”结构，宾补为不带to的不定式或v-ing形式。
如：She found that the wallet lay on the ground.
-- She found the wallet lie on the ground.
I heard that the birds were singing in the tree.
-- I heard the birds singing in the tree.
2. 当主语谓语动词是wish, decide, plan, agree, hope等，且主句和从句的主语相同时，从句可简化为不定式结构。
如：She agreed that she could help me with my Maths.
-- She agreed to help me with my Maths.
3 在连接副词/代词引导的宾语从句中，当从句的主语和主句的主语或和间接宾语一致时，宾语从句可简化为“连接副词/代词+不定式”的结构。
如：I haven’t decided when I will leave for Beijing.
-- I haven’t decided when to leave for Beijing.
Can you tell me how I can get to the station?
-- Can you tell me how to get to the station?
4. 在if或whether引导的宾语从句中，当主句和从句的主语相同时，从句有时也可简化为“whether + 不定式”的结构。
如：I am not sure if I will go with you.
-- I am not sure whether to go with you.
He doesn’t know whether he will stay here or not.
-- He doesn’t know whether to stay here or not.
Exercises for Chapter 3
I. Choose the best answer (选择最恰当的答案，用A、B、C或D表示，填入空格内。)
( ) 1. Benny is only seven, he doesn’t even know ____ electricity is.
A. why B. what C. which D. where
( ) 2. Electricity flows ____ a wire. It’s like water，in a way.
A. across B. through C. pass D. past
( ) 3. A: Can you get me a packet of electricity, please?
B: No, I ____.
A. mustn’t B. needn’t C. can’t D. couldn’t
( ) 4. Electricity is very dangerous. You must always ____ with it.
A. more careful B. be careful C. carefully D. are careful
( ) 5. There is ____ wrong with the computer. It doesn’t work.
A. anything B. nothing C. something D. some things
( ) 6. ____ he is only 8 years old, he knows more about science than his father.
A. But B. Because C. If D. Although
( ) 7. You get a bill _ water, gas, electricity every month.
A. for B. on C. with D. about
( ) 8. These ____ thick wires that are buried under the streets.
A. connect to B. connect with C. are connected to D. are connected
( ) 9. A: ____ I put the meat in the fridge?
B: No, you ____ cover the meat first.
A. May, may B. Must, may C. Must, must D. May, must
( ) 10. Can you think ____ an example to show that you are right?
A. of B. about C. over D. on
( ) 11. To save electricity, we ____ turn on more lights than we need.
A. couldn’t B. mustn’t C. needn’t D. may not
( ) 12. After a long way, we didn’t have ____ to play football.
A. electricity B. power C. heat D. energy
( ) 13. Do you know ____?
A. where does water come from B. how do we make electricity
C. who is looking foolish now D. why is there a grin on his face
( ) 14. I think electricity is ____ more dangerous than water.
A. much B. little C. many D. very
( ) 15. You should ____ do the work well.
A. be able to B. can C. must D. are able to
( ) 16. I have collected ____ information on how to save energy.
A. many B. a lot C. a number of D. huge amounts of
( ) 17. I agree with him partly, for some of his ideas are right. The underlined part means ____.
A. in this way B. in many ways C. in a way D. in the same way
( ) 18. At last my wallet was found lying under the bed. The underlined part means ____.
A. For a long time B. In the end
C. After a long time D. For the first time
( ) 19. Jenny looks really ____ these days because her father is in hospital.
A. happy B. sadly C. excited D. upset
( ) 20. Can you guess ____ the MP3 player last year?
A. how much did she pay for B. how much will she pay for
C. how much she will pay for D. how much she paid for

II. Complete the sentences with the given words box in their proper forms（用括号中所给单词的适当形式完成下列句子）
1. What would happen if there is no __________. (electric)
2. This star is __________ to the naked eye (肉眼) because it’s too far away from the earth. (visible)
3. Electricity is a good __________ (serve), but a __________ (danger) one.
4. How __________ I was to put my wallet on the top! Now it is missing. (fool)
5. “May I take your order?” the waiter asked __________. (polite)
6. We can get a bill for the amount of electricity we use __________. (month)
7. What’s the __________ between fiction books and non-fiction books? (different)
8. The camera needs two __________ to get the energy to work. (battery)
9. You’d better do your homework ___________. (careful)
10. He had no __________ for why he was late. (explain)

III. Rewrite the sentences as required（按要求改写句子，每空格限填一词）
1. Kitty has to do much homework on Sunday. (改为否定句)
Kitty __________ __________ to do much homework on Sunday.
2. He spent a whole morning cleaning the room. (划线提问)
__________ __________ did he spend cleaning the room?
3. Where does electricity come from? (改为宾语从句)
Do you know where __________ _______from?
4. “Will Betty come to our New Year’s party?” She asks. (改为宾语从句)
She asks __________ Betty __________ come to our New Year’s party.
5. Please tell me where I can buy the new bike. (改为简单句)
Please tell me where __________ __________ the new bike.
6. We should be careful with electricity. (改为同义句)
We __________ __________ be careful with electricity.
7. She could hardly understand this passage, ____ ____? (改为反意疑问句)
She could hardly understand this passage, __________ __________?
8. He looks very funny with that pair of glasses on. (改为感叹句)
__________ __________ he looks with that pair of glasses on.
9. You are not allowed to get out while the typhoon is coming. (改为同义句)
You __________ __________ out while the typhoon is coming.
10. You needn’t pay for that phone call. (改为同义句)
You __________ __________ to pay for that phone call.

IV. Cloze Text:
A) Choose the words or expressions and complete the passage（选择最恰当的单词或词语，
完成短文. ）
The water and the land are thought part of the earth surface (表面). The air is usually thought a kind of blanket __1__ the earth. But it is more than that. Maybe you have been in a cave deep in the earth. Did you think about