1. By building the city both deep into the ground and high above it, there would be room for far more people and everything else than there is in today´s two dimensional city.
    由于这种城市既建在地下深处，又造在地上高空中，所以能容纳的人和其它各种东西会比今天的平面城市多得多。

2. Why does a person standing in a bus or train tend to fall when a sudden start is made?
    一个人站在公共汽车或火车上，当车突然开动时，他为什么会倾倒呢？

3. With the hand held high in the air, hold the string so that the weight nearly touches the ground.
    把手高高举在空中握住绳子，让重物几乎接触地面。

4. When it did so, it sent sparks down to the ground and these immediately started a fire.
    当它这样做时，把火花送到了地面，这些火花立刻引起了一场大火。

5. Well, I measured the distance of ground, and calculated how deep it was to be dug, how broad, and how the earth to be thrown out.
    接着，我测量了一下距离，计算了一下该挖多深、多宽，以及怎样把土运走。

6. Water is in rock deep under the ground, in natural holding areas -- in storage.
    水深藏于地底下的岩层里、在天然蓄水区里 -- 水就储存在那里。

7. What remained of the life he had made was blown to bits though his home was more than a mile from ground zero.
    尽管他家与原子弹爆炸中心相距1英里，但是他所营造的生活中的一切还是被炸成了碎片。

8. When snow or ice was on the ground, it was impossible for him to walk, even with help.
    当路上覆盖冰雪时，即使有人搀扶，他也难以行走。

9. The flour was ground from barley.
    这面粉是用大麦碾成的。

10. These fall into the same category.
    这些独成一类。