英语第四单元知识点
1. In the 18th century, Benjamin Franklin cinducted a number of experiments in which he showed what electricity is.在18世纪，本杰明富兰克林进行了许多次关于电的实验。
[问]...in which he showed what electrivity is. in + which 引导定语从句，修饰先行词experiments。 这里which不能由that替换。
(2)...what electricity is 宾语从句，做show的宾语。
(3)A “许多，大量”，接可数名词复数，谓语要用复数形式;the “……的数量”谓语动词应该用单数。
例如：A number of peasants are working inthe fields with the sun burning in the shy. 许多农民顶着烈日在地里耕作。
2. Having realized that I could u a kite to aftract lightning. I decided to do an experiment. 当我意思到能用风筝来接收闪电后，我决定做个实验。
[问]Having realized that ... 在句子充当什么成分?
[答]Having realized that ... 现在分词短语做时间状语。(=when I had realized that I could u a kite to attract lightning, ...)
生活其实很简单 3. Most kites are made of paper, but a kite made of silk will last longer in weather with rain and strong winds. 大多数风筝是由纸做的，但用丝绸制的风筝在雨和大风的天气中持续的时间会长一些。
[问]made of silk 在句中作何成分?be made of 与be made from 有何区别?
恐龙名字大全 [答] made of silk 过去粉刺短语所定语，修饰a kite, he 由……构成(看得出原材料);be made from 由……构成(看不出原材料)。
4. The pieces should be just long enough to reach the comers of the handkerchief.那木头片的长度应该达到手帕的四个角。
[问]enough在句中如何用?reach是什么意思?
[答](1)enough to ..." 足够……的”， enough修饰形容词时应放在形容词之后。例如：kind enough 足够善良的;careful enough足够仔细的。
(2)reach v. & n. 达到;够得着。例如：out of reach够不着。
5. Add a tail to the frame and tie a long string to the cross so you can control the kite.在架子上加一个把柄，在十字架上栓一根长细绳以便你能够控制那风筝。
笞的拼音 [问]是什么意思?
[答]把……加到……。
例如：Plea add an article to the ntence, then it is correct now .请在这个句子中加上一个定冠词，然后它就对了。
6. THis ribbon, which must not get wet, will protect you from the electricity.这根丝带一定不能变湿，它是用来保护你不被触电的。
[问]which must not get wet 作何成分， 是什么意思?
[答](1)...which must not get wet ，非限制性定语从句做定语，修饰This ribbon.
报恩塔 (2)protect ... “保护……免受……”，相当于prevent ... from ...;stop ...;keep ...from。
例如：We should prevent our environment from being polluted. 我们应该保护我们的环境免受污染。
7. Around the world, animals are ud to test produce such as shampoo, skin creams and new cancer drugs. 在全世界，动物们被用来测试如洗发水，皮肤霜以及新的治癌药等产品。
[问]be ud to do ..., be ud to doing ... 和ud to do 有何区别?
[答]be ud to do ... 被用来做什么......
be ud to doing ... 习惯于做……
ud to do ...过去常常做……
8. They also believe that it is possible to u much fewer animals.
他们还相信用更少的动物测试是可能的。
[问]it is possible to do ...做……是可能的;
It is + adj. +to do ... it 是形式主语，真正的主语是动词不定式短语
例如：It is difficult to learn two foreigh languages. 学会两门外语是困难的。
It is impossible to walk on the moon. 在月球上行走是不可能的。
英语第四单元练习题
1、 带把伞可防晒。
Taking an umbrella will ________ _______ ________ ______ -______.学自由泳
2、 毫无疑问，他在说谎。
______ _______ ______ _______ that he is lying.
3、 意识到他一个人干不了这件事，他向我求助。
_______ ________ that he couldn’t do it himlf, he asked me for help.
4、 那位老师对全班的学生进行了数学测试。
The teacher ________ the whole class ______ maths.
5、 请你帮我选出一本杂志好吗?
Will you ________ _______ a magazine for me?
6、 我们可以在大厅拍照吗?
______ ______ ________ ______ take pictures in the hall?
7、 请在咖啡中加点糖。
回山倒海 Plea ______ some sugar ____ the coffee.
8、 妈妈开始做家务。
Mother is _________ ______ ______ her houwork.
9、 什么也阻止不了我们到这里来。
Nothing will __________ us _______ ________ here.
10、 他没有勇气违背他父亲的意愿。
He has no courage ______ ______ _______ his father’s will.
无线网络摄像机 11、 穿上这件外套。它可以御寒。
Put on this coat. It will _______ you ________ the cold.
12、 这些酒瓶是用玻璃制造的。
The wine bottles __________ glass.
13、 这种酒是用葡萄酿造的。
This kind of wine __________ grapes.
14、 注意在实验开始之前把一切都准备好。
________ _______ that everything is prepared before the experiment begins.
15、 每个队都有两次得分，比赛不分胜负。
Each team scored twice and the game_______ ______ ______ _______.
16、 为什么学生在闻从瓶子里冒出来的气味时要小心?
Why should students _______ _______ ________ from bottle?
17、 如果你眼睛里进了东西，该怎么办?
What ______ _____ ______ ______ when something gets into your eyes?
18、 它实在太昂贵了。
It is ______ ______ expensive.
19、 它既快又干净，而且不产生噪音，就像飞机一样。
It’s fast and clean and it does not make any noi, _____ ______ ____.
20、 那对经济(发展)有好处。比尔盖茨儿子
It ______ ________ ________ the economy.
21、 你使用的几乎每一种药都曾在动物身上试验过。
Almost every medicine you u ______ ______ ________ _______ animals.
