Everyobjecthasweight.Butthecenterofitsweightisnotalw...

問題詳情：

    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。根據文中圖2及第三段提示可以看出圖c與文中的圖2為同一類圖。

2. C。the Leaning Towner of Pisa不倒説明它的重心在AB直線上。

3. B。根據第一自然段最後兩句得知。

4. C。根據短文此題選C意為“重心不一定在物體的中間”。

5. A。文中主要告訴我們物體為什麼會倒塌的原因。

    C。本文是一常用語的習慣用法。與漢語一樣，一些常用語常被人們用來作比喻。

知識點：日常生活類

題型：閲讀理解