1. The population of the earth is increasing very fast. Man must make the earth support more people.
    地球上的人口在迅速增长. 人类必须使地球养活更多的人.

2. The earth revolves round the sun .
    地球绕太阳公转.

3. The earth rotates once every 24 hours.
    地球每24小时转一周.

4. The moon is the Earth´s satellite.
    月球是地球的卫星.

5. The damaged plane spiralled towards the earth.
    损毁的飞机旋转着跌向地面.

6. The air ten miles above the earth is very tenuous.
    地面上十英里处的气体是非常稀薄的。

7. The earth turns round at a uniform rate.
    地球以不变的速度旋转。

8. To escape from the Earth in a rocket, one must travel at seven miles per second.
    要乘坐一枚火箭飞离地球，火箭的速度要达到每秒7英里，

9. These ocean waves are among the earth´s most complicated natural phenomena,
    这些海浪属于地球上最复杂的自然现象。

10. The undulating waves of the open sea are generated by three natural causes: wind, earth movements or tremors, and the gravitational pull of the moon and the sun.
    公海上起伏的波浪是由3个自然因素构成的：风、地球的运动或震颤和月亮、太阳的引力。