15．Popular Science
常用句子
When we heat anything，It expands．
当我们给物体加热它就膨胀。
This wire inside an electric lamp is not made of copper but it is made of tungsten．
电灯里面的细丝不是铜丝而是钨丝。
Light travels very fast．It moves at 186，300 miles a second，that is 300，000 kilometers a
second
光速很快，每秒可行十八万六千三百英里，即三十万公里。
A ray of light usually travels in a straight line；but sometimes it bends．It leaves the air and
goes into the glass，then it bends．
一束光线通常走直线，但有时也弯曲，当离开空气进入玻璃时，它就弯曲。
Hydrogen burns easily in oxygen or in air．
氢气在氧气或空气中易燃。
The earth is one of the nine planets．转自:考试网 - [telnote.cn]
地球是九大行星之一。

Each of the nine planets turns on its own axis．They all go around the sun the same way．
九大行星都自转，它们又都围着太阳按同一方向转动。
Why does the earth always move round the sun and not fly off into cold space？The sun’s
gravitation gives the answer．
为什么地球一直围着太阳转而脱离不到太空去呢？太阳的牵引力能解释这个问题。
A vacuum is a space with nothing in it．
真空是指不包含任何东西的空间。
Aristotle said that heavy things fall faster than light things，but he was wrong．
亚里士多德说重的物体比轻的物体降落快，但他错了。
Some countries have large numbers of earthquakes．Japan is one of them．
有些国家地震频繁。日本是其中之一。
I’m very poor at physics, but Kate is good at it．
我对物理一窍不通，但凯特很在行。
I don’t like electricity，but I’m interested in the law of universal gravitation．
我讨厌电学，但我对万有引力定律感兴趣。wｗw.ExamＷ.CoM
Which is faster，sound or light？
哪一个快，声还是光？
I think physics is the most important subject．
我认为物理学是最重要的科目。