1. The blue water in the oceans and seas of the Earth makes a dramatic image.
    地球上大洋大海里的蔚蓝色的水构成了一幅激动人心的图画。

2. The rise of acquired immune deficiency syndrome (AIDS) around the earth has represented a major challenge to medical progress both in developed and in less — developed countries.
    全球艾滋病的蔓延无论在发达国家还是在欠发达国家都是对医学进步的重大挑战。

3. The Earth was formed about five billion years ago from a rotating, circular cloud of dust and gases such as hydrogen and nitrogen.
    地球的形成约在50亿年前，起源于一团循环旋转的尘埃和诸如氢、氧之类的气体。

4. The first animals on this living sphere, the Earth, were primitive marine animals, and then around 500 million years ago these sea animals developed shells.
    在地球这个有生命的星球上，最早的动物是原始海洋动物。后来，在大约5亿年前，这些海洋动物进化成甲壳动物。

5. The twentieth century began with powerful countries competing to take advantage of the Earth.
    从20世纪初起，各强国竞相利用地球资源。

6. These mysterious patches of light are still visible today and so bright that they have been seen from U.S. spacecraft in orbit around the earth.
    这些神奇的光带如今仍然可见，而且明亮得连在绕地球轨道飞行的美国飞船里都可以看到。

7. Then too, the triangle is one of only two places on earth where a compass needle points to true north rather than magnetic north, causing problems in navigation.
    除此之外，此三角是地球上惟一的两个罗盘指针指向真正北方而不是磁极北方的地段之一，这就造成了航行上的麻烦。

8. Now the slanting rays cover a much larger surface of the earth than the same number of rays coming straight down.
    此时，斜射的光线要比同样数量的直射的阳光在地表的照射面积大。

9. Now that they are no longer ignorant of the causes of the sickness of our planet, they seek ways to help the Earth, to give back what they take away.
    由于不再无视地球罹难的根源，人们正在寻求各种方法来治疗它，把自己取走的东西归还给地球。

10. Now everyone must protect planet Earth, a planet in danger.
    如今人人必须保护地球，保护这个身处险境的星球。