| 1. | It is the most pervasive compound on earth .
它是地球上最普遍的化合物。 |
| 2. | Why then should objects stay with the earth ?
为什么物体会呆在地球上呢？ |
| 3. | Many kinds of animals have vanished from the earth ..
许多动物已从地球上消失了。 |
| 4. | The steam engine altered the proportion of the globe .
蒸汽机变更了地球上的距离。 |
| 5. | There is air in every crack and hole on this earth .
地球上每个缝隙洞孔都有空气。 |
| 6. | Direction on the sphere is measured by azimuths .
地球上的方向是通过方位角测定的。 |
| 7. | A swift change had taken place on the earth for him .
在他看来，地球上发生了急骤的变化。 |
| 8. | The world's natural ecosystems act as a buffer .
地球上的自然生态系统起着一种缓冲的作用。 |
| 9. | Seen from the earth, the sun rotates in about 27 days .
从地球上观测，太阳的自转周期约为27天。 |
| 10. | Man spread from africa to nearly all parts of the globe .
人类几乎从非洲扩散到地球上的一切地区。 |
