Everyobjecthasweight.Butthecenterofitsweightisnotalw...

问题详情：

    Every object has weight. But the center of its weight is not always in the middle of the object. If the top of an object is heavier than its bottom, it will fall over easily. We say that its center of gravity（引力） is high. But if the bottom is heavier, it won’t fall easily. Then we say that its center of gravity is low.

    Look at the fist picture. This empty box must fall over, because its center of gravity (C) is not above the line of its bottom (AB).

    Now look at the second picture. There is some heavy iron at the bottom of this box. It will not fall, because its center of gravity is above its bottom.

  1. Please point out which box will not fall?

 2. From the passage, we can infer that the Leaning Tower of Pisa does not fall is because ____________

    A. the top of the tower is heavier than its bottom.

    B. The bottom of the tower is not heavier than its top.

    C. Its center of the gravity is still above the line of its bottom.

    D. Its center of the gravity is not above the line of its bottom.

 3. If an object has a low center of gravity, _______________.

A. it won’t fall             B. it won’t fall easily

C. it is certain to fall over    D. its top must be heavier

 4. Which of the following is true according to the passage?

    A. The center of the weight is always in the middle of the object.

    B. The center of the weight is always on the object.

    C. The center of gravity is not always in the middle of the object.

    D. The center of the gravity is always high.

5. The passage is mainly about ___________.

A. why things fall over    B. a low center of gravity  

C. a high center of gravity  D. that everything has weight

【回答】

1. C。根据文中图2及第三段提示可以看出图c与文中的图2为同一类图。

2. C。the Leaning Towner of Pisa不倒说明它的重心在AB直线上。

3. B。根据第一自然段最后两句得知。

4. C。根据短文此题选C意为“重心不一定在物体的中间”。

5. A。文中主要告诉我们物体为什么会倒塌的原因。

    C。本文是一常用语的习惯用法。与汉语一样，一些常用语常被人们用来作比喻。

知识点：日常生活类

题型：阅读理解