| 阅读理解。 |
| Even if you are a good high-jumper, you can jump only about seven feet off the ground. You cannot jump any higher because the earth pulls you hard. The pull of the earth is called gravity. You can easily find out the pull of the earth. If you weigh yourself, you will know how much gravity is pulling you. Since there is gravity, water runs down hills. When you throw a ball into the air, it falls back down. Because of gravity, you do not fall off the earth as it whirls (旋转) around. Then, can we get away from the earth and go far out into space? Now you can do it, because spaceships have been invented. Then the spaceship will go so fast that it can escape (逃出) the earth's gravity and carry you into space. |
| 1. 判断正（T） 误（F）。 ( )1.The weight of the earth is called gravity. 2. A good high-jumper can jump three meters off the ground, can't he? ____________________________________________________ 3. If the earth's gravity becomes smaller, will you become heavier or lighter? ____________________________________________________ 4. Why can a spaceship escape the earth's gravity? ____________________________________________________ 5. Put the underlined sentence in the passage into Chinese. ____________________________________________________ |