Unit 4 Astronomy: the science of the stars

I. 预习内容：

1. 了解宇宙科学、地球生命的起源，了解万有引力、黑洞和太空旅行等天文知识，培养学生对科学的兴趣、激发学生探讨科学的热情。

2. 掌握本单元的词汇和习惯用法。

3. 学会在日常交际中正确运用指示语。

4. 掌握名词性从句中主语从句的用法。

II.知识点

2. However, according to a widely accepted theory, the universe began with a "Big Bang'' that threw matter in all directions.

In all direction = in every direction 向四面八方

In one direction 朝同一个方向

In the direction of 朝某个方向

Under the direction of 在某人的指导下

According to the directions按照说明书

3. what's more important is that as the earth cooled down, water began to appear on its surface.

As 作连词，引导了时间状语从句。还可以引导时间、原因、方式、让步等状语从句。

1） 当......时候 相当与when/while，引导时间状语从句。但as较强调主句从句中的动作同时发生。

2） 随着 As time went on, many changes took place in my village.

3） 因为，由于 We don't know what to do as we were just visiting there.

4） 按照，如同 方式状语从句 You ought to do as Paul tells you.

5） 尽管，虽然 让步状语从句

引导的让步状语从句中，要用倒装，即把作表语的名词或形容词及作状语的副词放在句首（名词前不能加冠词）；有时，把谓语部分的动词原形提前。

Child as he is, he knows a lot.

Hard as he worked, he didn't pass the exam.

Try as you may, you won't succeed.

5. Later when the plants grew into forests, reptiles appeared for the first time.

For the first time 作状语，the first time 作连词引导时间状语从句。类似用法还有 every time /next time /each time ; the moment / the minute ; the first time / second ...last time; immediately/ directly; imstantly等

Eg: Each time I saw him, I thought of his poor brother.

He took off his coat the moment he arrived home.

6. Why they suddenly disappered still remaines a mystery.

r[fuzzy1]emain:

⑴ vi. 留下；剩下

⑵ link.v +n. /adj. / to be done 依然不变，继续，保持

e.g. Where he has gone remains a mystery.

The door remained locked.

It sounds like a good idea,but it remains to be seen whether it will succed.

The fact remains to be proved.

[fuzzy1]