This story is about a young man. He worked hard at his lessons. He was too busy. He didn’t have time to rest, so he was ill. Every night, when he went to bed, he closed his eyes and tried to sleep（睡觉）. But he couldn’t. He thought: “I must go to see the doctor.” He said to the doctor. “I can’t go to sleep at night.” “Try counting numbers. When you reach one thousand, you’ll be asleep.” The next day the man came back to the doctor’s office. “Well,” said the doctor, “How are you today?”
“Yes, he said,” I tried counting one, two, three. . . up to （直到）one thousand. But when I reached five hundred and sixty-nine, I began to feel sleepy (感到困倦). I had to get up and drank some tea. Then I went on counting up to one thousand. But I still couldn’t fall asleep.
小题1:The young man couldn’t go to sleep because ________ .
A．he didn’t finish his lessons
B．he worked too hard and was ill
C．he was worried about his homework
D．there was a lot of housework to do and he couldn’t have a good rest小题2:The doctor asked the young man ________ .
A．to count numbers before he went to bed
B．to put all numbers from 1 to 1000 together
C．to count numbers while he was lying in bed
D．to go to bed earlier小题3: The young man came back to the doctor’s office the next day because ___ .
A．he wanted to thank the doctor
B．he was better
C．he wanted to ask the doctor how to count the numbers
D．he still couldn’t go to sleep at night小题4:The young man ________ .
A．counted from 569 to 1000
B．counted from 1 to 569 and fell asleep
C．counted from 1 to 569 and got up to drink some tea
D．counted from 1 to 1000 and fell asleep小题5:The young man ________ in fact.
A．didn’t understand the doctor’s words.
B．couldn’t count numbers
C．didn’t try to sleep
D．wasn’t ill at all
，所以合力可以大于每一个分力也可能小于每一个分力，也可能介于两个分力大小之间，也可以等于每一个分力。