1. Perhaps it is the desire for solitude or the chance of making an unexpected discovery that lures people down to the depths of the earth.
    寻求独处的愿望或寻求意外发现的机会的欲望吸引人们来到地下深处。

2. Probably at one time the earth was blazing hot, like the stars we see in the sky at night.
    大概曾经有过一个时期，那时地球和我们看到的夜空里的群星一样的炽热。

3. Population is important to every person on Earth.
    人口情况对地球上的每个人来说都很重要。

4. People have more control over their surroundings than any other species on Earth.
    与地球上其他物种相比，人类更能控制其周围的环境。

5. Previously, mankind only used the Earth.
    从前人类只会利用地球，

6. Morocco and California are bits of the Earth in very similar latitudes.
    摩洛哥和加利福尼亚是地球上几乎同纬度的两小块地方。

7. Morocco and California are bits of the Earth in very similar latitudes,
    摩洛哥和加利福尼亚是地球上纬度极其相似的两个地方，

8. Many of their cultural values and ways of life include practices that return resources to the Earth.
    他们的许多文化价值观念和生活方式都包含向地球归还资源的做法。

9. Covering much of the earth´s surface is a blanket of water.
    地球表面主要被水覆盖着。

10. (If each calendar year were to be several days shorter than the time it takes the earth to go round the sun, the coldest winter days would soon come round in the middle of October in some twenty years!)
    （如果每个日历年都比地球围绕太阳旋转一周所花费的时间少几天，那么二十年后，冬天最冷的几天就会在十月中旬左右出现！）