问题 选择题

下列说法中正确的是

A.牛顿提出万有引力定律,并利用扭秤实验,巧妙地测出了万有引力常量

B.牛顿第一定律、牛顿第二定律都可以通实验来验证

C.单位m、kg、s是一组属于国际单位制的基本单位

D.长度、时间、力是一组属于国际单位制的基本单位的物理量

答案

答案:C

题目分析:A、牛顿提出万有引力定律,卡文迪许利用扭秤实验,巧妙地测出了万有引力常量;错误

B、牛顿第一定律是利用逻辑思维对事实进行分析的产物,不可能用实验直接验证;错误

C、在力学范围内,国际单位制规定长度、质量、时间为三个基本物理量,它们的单位米、千克、秒为基本单位;正确

D、力不属于国际单位制的基本单位的物理量;错误

故选C

点评:学习物理学史,可以让我们了解物理学建立的过程,加深对物理知识的理解。

阅读理解

阅读理解。

      

     Maybe your math teacher has already taught you how to find the center of a circle. It is not easy to

 learn and it takes some time to do so. Here is a way. First put a corner of a square piece of paper on a

 given circle and you will see the two sides the piece of paper meet the circle. And then you will get two

 points on the circle. You may name them Point A and Point B. Now draw a straight line through the Point

 A and Point B. You can get Line AB. Then, you must do the same thing a second time in a different place

  to get another two points, Point C, Point D and Line CD. You must write them down on the paper by

 yourself. You will find the center at once: the two lines cross at a point you may call it point O and this

 point is just the center of the circle. How about trying to see if it is easy to learn and remember this

 simple way of finding the center of a circle?

1. How many points are mentioned in the passage?

    A. Three      

    B. Five      

    C. Four

2. Which point is the center of the given circle?

    A. Point O        

    B. Point B      

    C. Point A

3. Does the center run through Line AB or Line CD?

    A. Line CD      

    B. Neither      

    C. Both

4. Which of the following is the right order to find the center of a given circle?

   a. Draw a straight line through the two points A and B.

   b. Do the same thing again in a different place.

   c. The two lines cross each other at a point.

   d. Put the corner of the square piece of paper on the given circle.

    A. a, b, c, d      

    B. c, a, b, d      

    C. d, a, b, c

5. When you use this way to find the center of a given circle, you need _____.

   A. a pencil, a square piece of paper and a pair of compasses

   B. a pair of compasses, a ruler and a square piece of paper

   C. a ruler, a pencil and a square piece of paper

单项选择题