问题 实验题

某同学在做“描绘小电珠的伏安特性曲线”的实验中得到如下一组U和I的数据:

(1)在图上画出I-U图线;

(2)从图线上可以看出,当功率逐渐增大时,灯丝电阻的变化情况是        

(3)这表明导体的电阻随温度升高而        

答案

(1)图“略”

(2)先不变后增大

(3) 增大

单项选择题 共用题干题
阅读理解

     This is a true story from Guyana. One day, a boy took a piece of paper from a box. He made a paper ball and pushed it into his nose. He couldn't get it out. He ran crying to his mother. His mother couldn't

get the paper out, either. A week later, the paper was still in the boy's nose. His nose began to have a bad smell.

     So his mother took the boy to a hospital. The doctor looked up at the child's nose, but she couldn't

get the paper out. She said she had to cut the boy's nose to get the paper out.

     The boy's mother came home looking sad. She didn't want her child to have his nose cut. The next

day she took the boy to her friend Sidney who lived in a house with an old lady called May. May wanted

to see the child, so the child let her look up his nose.

     "Yes, I can see it," May said. "It will be out soon."

     As she spoke, she shook some black pepper on the child's nose. The child gave a mighty sneeze and

the paper flew out. His mother was surprised. May told his mother to take the boy to the seaside for a

swim, for the salt water would go up his nose and stop the bad smell.

     So the lucky boy didn't have to go to the hospital to have his nose cut.        

1. After the boy pushed a paper ball into his nose, ____.

A. he took it out                

B. his mother took it out

C. he did nothing but cry        

D. he tried to take it out but failed

2. The paper ball stayed in the boy's nose for ____.

A. at most seven days            

B. less than seven days

C. more than seven days          

D. exactly seven days

3. Which of the following is TRUE?

A. The doctor helped to take the paper ball out of the boy's nose.

B. May succeeded in taking the paper out.

C. The boy's mother found some black pepper to solve the problem.

D. The boy had to have his nose cut at last.

4. The boy should be taken to the seaside for a swim because ____.

A. he needed to learn to swim

B. the sea water would stop the bad smell of his nose.

C. the sea water would wash out the paper ball.

D. he needed a rest