| 1. | Earthquakes take place far underground .
地震则发生在地球的极深处。 |
| 2. | We have discovered new horizons on earth .
我们已经发现了地球的新境界。 |
| 3. | The earth is shaped almost like an orange .
地球的外形几乎就象一个橙子。 |
| 4. | We can find the mass of the earth .
我们能够求出地球的质量。 |
| 5. | The earth 's circumference is nearly 25,000 miles .
地球的圆周约为25000英里。 |
| 6. | The lunar gravity is about one-sixth that on earth .
月亮的引力大约为地球的六分之一。 |
| 7. | But an extensive water surface is not two-dimensional .
然而地球的辽阔水面都不是平面。 |
| 8. | Why doesn't the earth's shadow hide it completely ?
为什么地球的影子没有完全把它遮住？ |
| 9. | The moon's grip on objects is not as strong as earth's .
月球对物体的引力，不象地球的强大。 |
| 10. | The diameter of mars is slightly over half that of the earth .
火星的直径比地球的半径稍大些。 |
