问题 多选题

如图为同一个打点计时器打出的四条纸带,则(  )

A.甲纸带加速度最大

B.乙纸带加速度最大

C.丁纸带平均速度最小

D.丙纸带平均速度最大

答案

从图中可以发现在位移相同的情况下,丁纸带所用时间最长,故丁纸带平均速度最小,所用C正确,D错误;

从图中可以发现纸带乙的相邻的时间间隔位移之差比最大,所乙纸带加速度最大,故A错误,B正确.

故选BC.

阅读理解

阅读理解

     Once there was a boy. He loved sweets very much. He always asked his father for sweets.

     The boy's father thought hard about how to stop the child from asking for so many sweets. A great man lived

nearby. The boy's father decided to take the boy to him. He might be able to make the child give up sweets.

     So they went to the great man. The father asked the great man to help him. But the great man liked sweets himself.

He told the father to bring his son back after a month.

     During the month, the great man tried to give up eating sweets. At last he did it. When the boy and his father

returned after a month, the great man had a talk with the boy. From then on, the boy did not ask for sweets any more.

     The boy's father felt surprised, "Why didn't you ask my son to give up sweets when we came to you a month ago?"

The man answered, "How could I ask a boy to give up sweets when I loved sweets myself?" In the last month I gave

up eating sweets."

     A person's example is always stronger than words. We should not ask others to do what we can't do ourselves.

1. The boy's father took his son to the great man because __________.

A. the man lived close to the house.

B. the man might give him some help.

C. the man was also fond of sweets.

D. the man had already given up sweets.

2. Which of the following is NOT TRUE?

A. The great man had a hobby of eating sweets.

B. The great man gave up eating sweets in a month.

C. The father and son came back to the man a month later.

D. The boy failed to stop eating sweets at last.

3. Which is the best title for the passage?

A. Eating sweets is bad for children.

B. A good way to give up eating sweets.

C. Giving up sweets is not difficult.

D. Examples speak louder than words.

判断题