Question

【题目】

The rockets take astronauts and man-made satellites into space. The satellites are used for communication, weather monitoring and research. But how do satellites stay up without Falling down?

There are two opposite forces acting on the satellite. One of them is the force of gravitation(地心引力), which tries to pull the satellite toward the earth. The other force is created by the rotation (旋转)of the satellite around the earth. This force tries to take the satellite away from the earth. With these two forces, the satellite goes round and round. The gravitational pull of the earth is like a rope which keeps the satellite from flying away.

Everything that goes up has to come down. It is only a matter of time before a satellite comes back to the earth. As time goes by, the satellite loses its speed, which makes the gravitational pull stronger than the force pulling it away. This makes the satellite crash (坠落)down to the earth.

【1】The force that pulls the satellite towards the earth is created by ________.

A. the earthB. the satellite itself

C. the rotation of the satelliteD. the rope

【2】Why can't the satellites fly away?

A. Because of the force from the earth.

B. Because the satellite is too big.

C. Because of the force created by the rotation of the satellite around the earth.

D. Because people on earth have made ropes to tie the satellites tightly.

【3】Which of the following is TRUE according to the passage?

A. There are four forces acting on the satellite.

B. The force of gravitation makes the satellite go round and round.

C. As time goes by, the satellite will finally fall down.

D. The satellite will stay in space forever.

Answer 1

【答案】

【1】A

【2】A

【3】C

【解析】

火箭把人造卫星送入太空，那人造卫星是怎样保持上升而不下落的呢？短文中作者给我们解释了这其中的道理。

【1】细节理解题。根据短文第二段中One of them is the force of gravitation(地心引力), which tries to pull the satellite toward the earth. 可知，把卫星拉向地球的力是地心引力，这种力是地球引起的，故应选A。

【2】细节理解题。根据短文第二段最后一句话The gravitational pull of the earth is like a rope which keeps the satellite from flying away.可知，地球的引力就像一根绳子，它保持卫星不会飞走。由此可知应选A。

【3】推理判断题。根据短文最后一段As time goes by, the satellite loses its speed, which makes the gravitational pull stronger than the force pulling it away. This makes the satellite crash (坠落)down to the earth可知，随着时间的推移，卫星的速度越来越慢，这就使引力比拉力更强，所以卫星为坠落到地球上。因此C选项是正确的。

这是一篇科普类的说明文，短文中讲述了人造卫星进入太空后能保持上升而不下落的原因。这种科普类的文章在理解上稍有难度，它与学生们的其他学科知识有关，这些背景的知识可以帮助学生理解短文。做题时，应尽力把握文章主旨，了解作者的写作意图。对长难句进行仔细分析，弄清楚句意。这篇短文中出现的生词不是很多，有些生词注释了汉语意思，减少了阅读的难度。题目设置有细节理解题和推理判断题，细节题考查学生们对文章事实信息的理解，答案常可以直接在原文找到。如第2小题，根据题干中关键词can’t fly away可以定位到短文第二段最后一句话，The gravitational pull of the earth is like a rope which keeps the satellite from flying away.可知，地球的引力就像一根绳子，它保持卫星不会飞走。A选项中the force from the earth 与原文 the gravitational pull of the earth同义，都是指“地球引力”，故应选A。