▲百分数作主语时，即percent后有数词时，应注意两点：一是percent不能用复数形式；二是谓语动词的单复数。如果percent of后的名词为单数，谓语动词用单数；其后的名词为复数，谓语动词则用复数。如：① About 70 percent of the surface of the earth is water.地球表面大约百分之七十是水。② Eight percent of the students are absent today.今天有百分之八的学生缺席。
【注】percent可作为副词用，在句中作状语。如：①I notice you don't say that you're a hundred percent convinced yourself. 我注意到你没有让你自己完全信服。 ② Prices have risen 5. 5 percent in the past year. 过去一年物价上涨了5.5%。③ I think it's ninety percent probable. 我想有百分之九十的可能性。
【注】percent也可作形容词用，在句中充当定语。如： I paid him six percent interest.我付给他百分之六的利息。
【注】percentage意为"百分比"，多与of连用。如果连用的名词是复数，后面的动词就用复数形式，否则用单数形式。如：① What percentage of babies die of this disease every year? 每年婴儿死于这种疾病的百分率是多少? ② What percentage 0f his income is paid in income tax? 他的收入有多大比例用来交所得税?
8. Marine life is incredibly rich and varied. 海洋生物极其丰富多样。(p.19 第一段 第3行)
▲varied是由动词vary变化而来的过去分词，在句中作定语或表语。如：① The menu is varied and cheap.菜单上的菜花样很多也很便宜。② They made varied efforts to bring about a peaceful solution of the problems. 他们做了种种努力来和平解决这些问题。③ They are rich in content and varied in style.它们内容丰富、风格多样。④ He had had varied training and had held many offices.他受过多种训练并担任过多种职务。
▲动词vary意为"有差异""有变化"时，是不及物动词。如：① Courses vary according to the needs of the students. 课程根据学生的需要而不同。②People vary very much in their ideas. 人与人的想法差别是很大的。③ The answers given by different people vary greatly.不同人作出的回答，差别非常大。
▲vary可作及物动词，意思是"使......有变化""变换"。如：①You should vary your diet. 你的饮食应经常变换花样。② She varies her dress as fashion changes. 她的衣着随潮流而变化。
【注】vary充当及物动词时，可用现在分词作定语。如：varying prices 不断变化的价格。
9. There are about five million species in the oceans and we have yet to learn much about them. 海洋里大约有500万种生物有关这些种群的情况，我们还有许多东西要了解。(p.19第一段第4行)
1) species
▲ species意为"种""类"。单复数同形，主要指生物学上有相同特征的动植物品种、种类。如：① The agri- cultural extort has developed a productive species of rice.这个农业专家培育出一种高产水稻品种。② Pandas are an endangered species.熊猫是一种濒临灭绝的动物。③ Some species of animals have become extinct because they could not adapt to a changing environment.有一些动物已经灭绝了，因为它们不能适应环境的变化。
【注】species可用来表示"人类"。如：① The use of nuclear weapons is a horrible threat to the species. 核武器的使用对人类是一个严重的威胁。② The protection of our environment will benefit the human species.保护环境有益于全人类。
【注】 species在口语中表示"种类"，相当于a kind，a type，a sort。如：① Various species of business advertise- ments on the television sometimes make TV programs rather dull. 电视上五花八门的商业广告有时使电视节目十分乏味。②A strange species of car attracted the attention of people.一种形状奇特的轿车引起了人们的注意。
【注】英语中还有specie这个词，不要把它误认为是species的单数， 这是两个完全不同的词。specie意为"硬币"。
2) yet在肯定句中的意思和用法。
▲yet一般用于否定句和疑问句，意为"还""已经"。如： ① I don't want to go away yet.我现在还不想离开。② The moon had not yet risen.月亮还没有升起。③ I wonder if she's started yet.不知她开始了没有。
▲在个别情况下yet也可用在肯定句中，意为"还""又"。如：① It was too early yet to tell anything. 现在要说什么还为时过早。② I have a few more pages to read yet. 我还有几页书要看。③ Much yet remains to be done. 还有很多事等着去做。
▲yet可用来表示将来还可能发生某事，意为"迟早""终归"。如： ① The plan may yet succeed. 这个计划还可能成功。 ②It will be colder yet before spring comes. 春天到来之前还可能更冷一些。③ The thief will be caught yet.小偷迟早会被抓住的。
▲yet可作连词用，意为"但是""然而"。如：①Jane said she Was ill, yet I saw her in the street just now. 简说她病了，但我刚才还看到她在街上。② I gave him all he asked for，yet he is still not satisfied. 我给了他所要的一切，但是他仍然不满意。
▲yet也可以和and连用，表示"但是"。如：He's plea- sant enough, and yet I don't like him. 他够招人喜欢的，但我不喜欢他。
【注】still，already和yet都有"还""仍然"之意，但是有差别。still暗示对某事件持续时间比预料的长而感到惊讶。如：The coffee is still hot. (咖啡还是热的。) already用于表达对某事物发生时间比预料的时间早而感到惊讶。如：The coffee is cold already．(咖啡已经凉了。) yet一般用于否定句和疑问句中，在正式语体中有时可代替still。如：I have still／yet to hear the truth. (我仍然未被告知真相。)
10. Life in the ocean ranges from the tiniest plankton all the way up to giants like sharks and whales.海洋里的生物中从微小的浮游生物到巨大的动物如鲨鱼和鲸鱼都有。(p.19 第一段 第5－6行)
▲range在本单元中作不及物动词用，意为"在一定范围、幅度内变动"。range的此种用法无进行时态，常与介词from...to...或between连用。如：① Sentences today range from 5 or 6 words to 70, with the majority not far from 20. 现在的句子长度从五、六个词到七十个词不等。不过大多数句子的长度在二十个字左右。② His interests ranged from chess to surfing. 他的爱好从下棋到冲浪，无所不有。③ Their ages ranged from 25 to 50. 他们的年龄在二十五岁到五十岁之间。④ The temperature ranges between 0℃and 30℃.气温在摄氏零度到30度之间。
* range后接介词over时表示"漫游..." "涉及""包括"。如：①We ranged over the hills and valleys. 我们在山上和山谷中漫游。② Our conversation ranged over many topics. 我们的谈话涉及许多话题。
【注】range 作"漫游"解释时，可作为及物动词用。如：He spent the summer ranging the countryside. 他在乡间漫游，度过了夏天。
▲ all the way意为"一直""始终"，也可以用the whole way。如：① There being no bus, he had to walk all the way home. 没有公共汽车，他不得不一直步行到家。② I'll support him all the way whatever happens. 不管发生什么事，我将始终支持他。③ The dog has been with me all the way. 这条狗一直跟着我。
▲ up to此处是与from连用的。up to单独使用时有"直到""至多"之 意。如：① It could be up to two years before the project is completed.可能需要两年时间这项工程才能完成。② She was here up to a few minutes ago. 她直到数分钟前还在这里。③ Our minibus can hold up to eight people. 我们的小车能容纳8人。④ Up to now I've never met him. 一直到现在，我还没见过他。
【注】up to有很多意思，常见的还有"忙于...""由......决定、负责"。如：① What have you been up to all day while I've been busy? 我整天忙着的时候你在干什么? ② Go and see what these girls are up to.去看看这些女孩子在干什么。③ It's up to you whether you decide t0 take the job. 要不要这份工作由你自己决定。④ It's up to you to break the news to him. 该由你把这消息告诉他。
【注】up to还可作"及得上""可以与......相比较"解。如：① This new book of Green's isn't up to his last. 格林的这本书不如上一本好。② He is not up to his father as a scholar. 作为学者他不如他父亲。
上一页 [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] 下一页
+《高二英语下知识点总复习教案》相关文章
- › 高二英语语法讲解：倒装句
- › 高二英语选修8unit2词汇表
- › 高二英语必修1课文翻译（人教新课标）
- › 高二英语教学心得
- › 高二英语必修2翻译答案
- › 高二英语必修五语法练习
- 在百度中搜索相关文章：高二英语下知识点总复习教案