相对于高一，高二课程的难度提高了不少，知识容量大增。只有扎实掌握这部分知识才能较为轻松地完成高三总复习。这就对同学们高二期间的英语学习提出了更高要求。以下是小编给大家整理的高二英语选修七第三单元知识点，希望大家能够喜欢!
高二英语选修七第三单元知识点1
Ⅰ.Hot words and hot phrases常用词与常用词组
1.Medical studies show that AIDS virus cannot be transmitted via the following routes：cups，glasses，toilet seats，swimming pools，mosquitoes，other insects or blood donation.(P.49)
2.AIDS is a disease that breaks down the body's immune system and leaves a person defenceless against infections and illness.(P.51)
3.People get AIDS after having been infected with the HIV virus.(P.51)
4.People transmit HIV by having unprotected sex，by receiving infected blood transfusions or，as in Xiaohua's case，through birth.(P.51)
5.Xiaohua's mother contracted the HIV virus when she was 28，and she died of AIDS only three years after Xiaohua was born.(P.51)
6.The disease is spreading faster in Africa and parts of Asia，mainly because of a lack of proper health care，prevention and education.(P.51)
7.The drugs that are available are much too expensive and difficult to find.(P.51)
8....but she does not let that knowledge discourage her.(P.51)
9.She also goes to visit other AIDS patients in hospitals across the country to support them and cheer them up.(P.51)
10.The disease is not the only thing that AIDS patients have to suffer from.(P.52)
11....that can persuade hospitals and companies to allocate more funds for AIDS research and education.(P.52)
12.Xiaohua has learnt to live with HIV and the fact she will eventually get AIDS.(P.52)
13.Two years ago，Dr Richards had asked me a great many questions and had taken samples of my blood.(P.55)
14.Mum held my hand and I saw that she was weeping.(P.55)
15.Cancer is a disease that begins in cells.(P.55)
16.In my body，the production of cells is disrupted.(P.55)
17.Doctors do know that cancer is not caused by injury and is not contagious—it does not spread from one person to another.(P.55)
18.The cancer in my body has been defeated for the moment.(P.55)
19.Living with cancer has made me realize how precious life is and how important it is for us to take every chance to live life to the fullest.(P.55)
20.Every day is a new opportunity and I have learnt to appreciate every minute of each day.
Ⅱ.Language points and grammar focus语言点和语法重点
A.Language points语言点
1.HIV/AIDS is incurable...(P.49)
AIDS is a disease that...leaves a person defenceless against infections and illness.(P.51)
本单元中由前缀或后缀派生出的反义词的小结
2.People get AIDS after having been infected with the HIV virus.(P.51)
完成时的动名词的被动式的内涵及用法
3.As with most diseases and disasters，the young suffer the most.
“定冠词 + 形容词/过去分词”表示“一类人”的用法的小结
4.I had been feeling sick for a long time and my mum had taken me to hospital to have me examined.(P.55)
1)过去完成进行时的内涵及用法
2)“to have + 宾语 + 过去分词”的两个内涵及用法
5.The treatment was successful and I was able to go home after exactly fourteen months，two days and six hours in hospital.(P.55)
was/were able to do与could do在内涵上的区别及各自的用法
6.I have been living with cancer for two years and...(P.55)
现在完成进行时的内涵及用法
Ⅲ.Skills of the four essential abilities：listening，speaking，reading and writing听、说、读、写四项基本能力的学习技巧
1.Listening：Master the main idea of a long dialogue through the inner connections among the questions so as to have better understanding of the questioned details
从各设问间的内在联系把握较长对话的中心思想，更好理解各检测点的细节
2.Speaking：Talk about deadly diseases and attitudes towards AIDS，cancer，etc.
关于那些致命疾病及对待艾滋病、癌症等的态度的谈论
3.Reading：Make full use of informational words and phrases
充分利用信息词
4.Writing：How to write a personal narrative
如何写一篇个人经历过的叙述性故事
高二英语选修七第三单元知识点2
一、不定式做主语：
1、不定式做主语一般表示具体的某次动作。===动名词doing 表示习惯的，经常的动作。
e.g: To finish the building in a month is difficult.
To do such things is foolish.
To see is to believe. (对等)
注: 1). 不定式作主语时,谓语用单数
2). 当主语较长，谓语较短时，常用it做形式主语，而将不定式放到谓语的后面。
it做形式主语，不定式放在谓语动词之后常用于下列结构中：
(1)It is/was +adj.+of sb. to do…
(2) It is +adj.+for sb.+to do…
It is easy / difficult / hard / foolish / unwise / right / wrong / unnecessary
(3) it is +a +名词+ to do...
It is a pity / a pleasure / a pleasant thing / one’s duty / an honor / a shame / a crime / no easy job… to do
It takes (sb.) some time / courage / patience …to do…
It requires courage / patience / hard work… to do…
_注意: probable 和 possible 均可作表语，但possible可以用不定式作真实主语， 而probable不能用不定式作真实主语。
It is probable for him to come to the meeting.(错)
It is possible for him to come to the meeting.
It is possible / probable that he will come to the meeting.
二、不定式做表语
主语是以aim duty hope idea intention plan job suggestion wish purpose task 等为中心词的名词词组 或以 what 引导的名词性从句表示，后面的不定式说明其内容, 不定式作表语常表示将来或现在的动作或状态。
eg :My idea is to climb the mountain from the north.
Your mistake was not to write that letter.
What I would suggest is to start work at once.
三、动词不定式作宾语
以不定式结构为宾语的动词有：
ask, agree, care, choose, demand, decide, expect, fail, help, hope, learn, manage, offer, plan, prepare, pretend, promise, refuse, want, wish等只能用动词不定式作宾语