B3U4
一、重点单词及词组
1. be to do sth.
① 将要做某事，指预定先安排好的计划或约定
I'm to see him today at 6 o'clock．
②表示义务、命令、禁止或可能性等意思，接近于should、must 、have to eg.
All these things are to be done.
③表示将来必然要发生的事，以为"注定"
You 'are to cope with money if you choose become an accountant（会计师）．
其他用法：
①长辈要求晚辈做某事
②用于第一人称疑问句，表示征求对方意见 Am I to go with you?
2.violent adj．暴力的，猛烈的
拓展：a violent storm暴风骤雨
take…by violent强夺
3．in time 及时 后接"for n．"或动词不定式
on time准时
拓展：ahead of time提前
at one time曾经
for time on time 间或
4．fundamental adj. 基本的，基础的
be fundamental to
对．．．必不可少
5．harmful adj．有害的
be harmful to 对．．．有害
＝do harm to...
6．for the first time 第一次
It/This is／was the fist．．．time＋从句（从句中要用完成时态）
It is (was) the first time that I have (had) been to Beijing.
7． exist vi. 存在，生存
exist in 存在于...中
exist on＝live on
靠．．．为生
existence n．存在，生存
come into existence /being
产生，形成，出现
in existence 现存的，现在的
① exist常用其"动词－ing"形式做定语，表示现存的，现在的
② exist不用于被动结构也不用于进行时态
8．in one's turn 轮到某人，接着
拓展：by turns 轮流
in turn 依次
take turns to do sth. 轮流做某事
Finally, he got the concert ticket in his turn．
Prevent…(from) doing...
阻止．．．做某事
同义词组：
stop…(from) doing...，
keep ...from doing... （此句型中from不能省略。）
9．puzzle n.＆v．难题，谜
be in puzzle不知如何是好
vt.．使迷惑
puzzle about苦苦思索
Puzzled某人感到困惑的
puzzling 令人迷惑的
10．cheer up 使振奋
cheer…on… 为…加油
cheer up 既是及物动词短语也是不及物动词短语，接代词做宾语时，要把代词放在中间
She tried to cheer him up.
11．twice…as…as… …两倍于…（一种倍数表达方法）
He is nearly twice as heavy as you.
他几乎是你的两倍重。
常见倍数表达法：
①A is 倍数 形容词比较级 than B
②A is 倍数 as 形容词原级 as B
③A is 倍数 the size／weight／height／length／which… of B
12．break out 突然开始，爆发
break up结束 break though突破 break away from 脱离 break into 强行进入
13．watch out for 密切注意，当心，提防（尤其用于提醒）
Watch out for the stop here．
当心，这里有台阶。
14．辨析give birth to 与be born（指出生时间和地点） borne （bear的另外一个过去分词）
①give birth to = bear (vt.)是表示"生产，生下"，其宾语是表示婴儿或幼崽的词语，主语是表示雌性或人类女性的词语。
She gave birth to a healthy baby girl last month.
②be born 表示"出生"主语通常是被生下来的人或动物。
She was born into a musical family．
③ 指生孩子用 borne eg.
She has borne three children.
15．now that = since 引导原因状语从句（既然，由于）
Now that I have made this first visit, I hope I can come many more times．
表示原因的连词：
now that = since ; because ; as ; considering(that) ; in that; for（并列连词，不能引导原因状语从句）
引出原因状语的短语：
due to ；thanks to；because of ；as a result of；account of等
三、重点句型
1．What it was to become was uncertain until between 4.5and3.8 billion years ago when the dust settled into a solid globe．
随后它会变成什么也不会有人知道，直到38—45亿年前这因尘埃才慢慢地形成一个固定的球状物。
① what it was to become是一个主语从句，做主语。
② be to do表将要，until直到…时候
③ "when the dust settled into a solid globe"是定语从句，修饰时间"4.5and3.8 billion years ago"
2．The earth become so violent that it was not clear whether the shape would last or not．
地球变得如此激烈，以至于不知道这种形状是否会继续下去了。
So...that引导的结果状语从句
3．There were in time to produce carbon dioxide，nitrogen，water vapour and other gases，which were to make earth's atmosphere．
他们最终产生了二氧化碳、氮气、水蒸气和其他多种气体，从而形成了大气层。
① which引导非限制性定语从句
② in time for n．
4．So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved．
所以在未来数百万年中，生命能否在地球上延续，取决于这个问题能否得到解决。
① 此处whether不能换做if
② to come为动词不定式做后置定语修饰millions of years
5．It is unlike sb to do sth
做某事不是某人平常的样子．
6．There is no harm in （one's）doing sth．某人做某事无害
7．It does no harm of sb to do sth． 某人做某事无害
8．To make matters worse…更糟糕的是……
He missed the train to work ．To makes matters worse，he lift his papers（文件） at home．
