3 Planet Earth

Planet Earth

地球

A place in space. You live on Earth, one of the eight planets that move around the Sun. Scientists think that Earth is the only planet with anything living on it.

空间中的一个位置。你生活在地球上，地球是围绕太阳运行的八颗行星之一。 科学家们认为地球是唯一有生命存在的星球。

All About Earth. Things can live on Earth because it has the right mixture of heat, air and water. The Sun keeps the planet warm. Living things — people, animals and plants — all need air to breathe. Over half of the Earth is covered in water. All living things need water to stay alive.

关于地球的一切。生物能在地球上生存是因为地球上有合适的热、空气和水的混合物。 太阳使地球保持温暖。 生物——人、动物和植物——都需要空气来呼吸。 地球的一半以上被水覆盖。 所有生物都需要水来维持生命。

The middle of the planet is called the core. It is very, very hot here. Around the core is the mantle. The rocks here are so hot that they are slightly squishy. The mantle is covered with a thin layer of solid rock, called the crust.

地球的中间称为地核。 这里非常非常热。 地核周围是地幔。 这里的岩石太热了，所以有点软。 地幔上覆盖着一层薄薄的固体岩石，叫做地壳。

Moving Earth. The Earth's crust is made up of pieces. The pieces of crust slot together around the Earth. Very very slowly, the pieces of crust move around. The place where the pieces slide past each other is called a fault. Pieces of crust can move smoothly along a fault, but sometimes they get jammed.

移动地球。地壳是由碎片组成的。 地壳的碎片在地球周围缝在一起。 地壳的移动非常非常缓慢。 这些碎片相互滑动的地方被称为断层。 地壳可以沿着断层平稳移动，但有时会被卡住。

Jammed pieces can suddenly start to slip past one another. The land above trembles and cracks. This is called an earthquake. Big earthquakes can destroy buildings and tear up roads. There are even 'earthquakes' on the moon. These are called moonquakes.

被卡住的碎片可能突然开始相互滑过。 上面的土地颤抖着，裂开了。 这就叫做地震。 大地震可以摧毁建筑物，撕裂道路。 月球上甚至有“地震”。 这些被称为月震。