Unit 4 How Life Began on the Earth Language points
1.No one knows exactly how the earth began, as it happened so long ago. as在这里表示原因, 意思是“因为” As he was ill, he needed more help. 仿
No one knows what he was saying, as it was too hard.
2.However, according to a widely accepted theory, the universe began with a “Big Bang” that threw matter in all directions. 1) begin with=start with：“以……开始”. 2)to begin with =to start with 可以单独使用, 表示“首先; 第一; 起初; 最初”.在句中作 时间状语. e.g. To begin / start with, I couldn’t understand him at all.
in all directions. =in every direction/directions? 朝四面八方 译：The enemies ran away in all directions. 敌人四处逃窜。 拓展： 我是路痴 ① I’m terrible with directions: __________ ② a sense of direction: 方向感 _______ ③ 在某人的指导下: ______ under one’s direction
3. What it was to become was uncertain until between 4.5and 3.8 billion years ago when the dust settled into a solid globe .
What it was to become was uncertain… be to do
be to do sth.
be + doing:_________ 正在… be + done:__________ 被动
(1)表示 禁止，命令 eg. You are not to smoke in this room. You are to be back by 10 o’clock.
All these things are to be answered for （偿还）.
（3）表示 “将”、“计划”、“安排”。(意思接近于 be going to) 如： . The students are to meet at the school gate tomorrow. （4）应该 should You are to look after the little children
. be to do : are to report ? You ______________this to the police. ? 你应该报警 ? They are ________________next month. to be married ? 他们计划于下个月结婚。 ? 2. The professor ____a lecture at Wuhan University next weekend. A. give B. gives C. is to give D. being given
【精提取】What it was to become是what引导的主语从句， what在从句中作become的宾语。
【巧应用】 使大家惊奇的是他竟没 有参加会议。 ________ ________ ________ ________ ________he didn’t come to the meeting. 答案：What surprised everybody is that
1. ______________________ （使大家吃惊的是） What surprised everybody is that he didn’t come to the meeting. 2. ___________ What he did （他所做的）added to our difficulty.
4.The earth became so violent that it was not clear whether the solid shape would last or not.
地球开始变得激烈动荡，不知道这个固体形 状是否会继续下去。 n. 固体 (solid, liquid, gas )
solid: adj. 固体的, 结实的,
6. What is even more important is that as the earth cooled down, water began to appear on its surface.
cool down 变凉, 冷却,平息，冷静
After a day in the sun, he liked to cool ________ down in the sea.
cooled down her anger. His words _____________
7.Water had also appeared on other planets like Mars but, unlike the earth, it had disappeared later.
8.It was not immediately obvious that water was to be fundamental to the development of life. 水会对于生命的发展起关键作用,这一点在当 时并不太明显.
9. What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas. 1) allow … to do …= permit …to do… 2) harmful adj. harmless harm n./v. be harmful to sb./sth. = do harm to sb. /sth.=do sb/sth harm 对…有害
过多的二氧化碳对环境有害. Too much carbon dioxide is harmful to the environment.
does harm to
10.This produced a chain reaction, which made it possible for life to develop. 1) chain reaction 连锁反应 2) Make it possible for life to develop. 使生命的发展成为可能 make it + adj./ n.+. to do sth.
make / find / feel / think / consider
组长让我们可以一起合作. made it possible for us The group leader_____________________ to work together.
老师让他们容易地明白那个问题. The teacher made it easy for them to understand _________________________________. the question
12. … which encouraged the later development of early shellfish and all sorts of fish.
all sorts of =all kinds of 各种各样的
13.Others, called amphibians, were able to live on land as well as in the water. 另外一些叫作两栖动物,它们既能在活水里生 存也能在陆地上生. A as well as B表示“(除B之外)A也; 既B又 A”. 如: I’m learning French as well as English. 我学英语之外还学法语.
He grows flowers as well as vegetables. 他既种菜也种花. “就远原则”： likes (like) rock music. He as well as I ______
15.They produced young generally by laying eggs.
它们一般是通过孵蛋而繁衍后代的. lie, lie , lay 的区别如下:
第三 人称 单数 lie lies lie lies
过去 式 lied lay laid
过去 现在分 中文 分词 词 释义 撒谎; lying lied 谎话 lain lying 躺; 位 于 放置; laying laid 下蛋
18. small clever animals, now with hands and feet, appeared and spread all over the earth. （1）vi. （消息等）传开，流传。如： The news spread through the school very quickly. The fire spread from the factory to the house nearby.
（2）v. “使伸展，延伸，张开”，常 与out连用。
He spreaded out his arms to welcome us.
19.Thus they have, in their turn, become the most important animals on the planets thus adv. 因此；从而 She studied hard, ____________________ . thus she got high marks
2) In one’s turn 轮到某人 in Sam's turn It will be _______________ to be on duty tomorrow.
20. They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space. 阻止某人做某事 : prevent sb. (from) doing sth. stop sb. (from) doing sth. keep sb. from doing sth. 注意：keep sb. from doing sth.中from不
1) We must prevent them from making trouble. 2) You should prevent the child from injuring himself.
21.Whether life will continue on the earth for millions Of years to come will depend on whether this problem can be solved.
depend on : 依赖，
depend on sb. 依靠,相信某人 depend on sth. 取决与某物
我们都靠你来做决定了． depend on you We’ll all _______________to make a decision. 明天是否能开校运会取决与天气． Whether to hold the sports meeting or not will _______________________. depend on the weather
一.单词拼写 1. There is too much ________(暴力) on TV. 2. With the d ________ of economy, people’s living standards are higher now. 3. Every night he observes the space through a t_______. 4. The illness is s______ through the village. 5. One cannot e________ without air. 6. You will _______ (逐渐地) get used to the weather here. 7. By the time they reached the top of the mountain, they were ________ (精疲力尽). 8. There is a big underground railway ________(系统) in London, which is good for travelers. 9. Zhang Heng was one of the most famous Chinese a______ in the world. 10. The mammals _______ (繁殖) when the animals, harmful to them, disappeared.
in all directions,go by,give birth to,in time,depend on,prevent...from,as well as, be different from，escape from，watch... doing,masses of,because of
1.Whether life will continue on the earth
for millions of years to come will __________ depend on
whether this problem can be solved. 2.If you put your heart into it ，you’ll succeed _________. in time
3.There were ___________ masses of people in the shops yesterday.
4.Nothing can _______ ____ being prevent their plans from carried out. 5.We _______ setting behind the trees watched the sun _______ and the evening fell.
6.Our sons are very _______________ different from each other.
7.We spent three hours waiting in the rain ___________ because of you! 8.As time ________,I began to realize what I went by did was wrong.
Homework 1.完成课本P28 练习1至练习3。 2. 课本P98 单词multiply 至gentle 三 加一。