问题 选择题

下列说法中错误的是(  )

A.所有固体熔化时温度都保持不变

B.所有气体在温度降到足够低时都可液化

C.蒸发、升华都有致冷作用

D.液体沸腾时对它继续加热,温度不升高

答案

A、固体分为晶体和非晶体,晶体熔化时,吸收热量,温度保持不变.非晶体熔化时,吸收热量,温度不断升高,该选项说法错误;

B、使气体液化方法有降低温度,所以所有气体在温度降到足够低时都可液化,该选项说法正确;

C、蒸发和升华都需要从周围吸收热量,所以蒸发与升华都有致冷作用,该选项说法正确;

D、液体沸腾时的特点是吸收热量,温度保持不变;所以液体沸腾时对它继续加热,温度不升高时,该选项说法正确.

故选A.

阅读理解

Paul and I live in the same building. His room is on the sixth floor but mine is on the fifth. He’s very careless and sometimes he gets into trouble.

Last Friday afternoon the young man and his friends went to spend the weekend on a wild island. They could swim, fish, play the guitar and sleep in the quiet place at night. They enjoyed themselves there and could do anything they wanted. On the third morning they decided to get back to the land. But their boat hit a rock and soon went down. With the villagers’ help, they swam to the bank. Luckily none of them was hurt. They took a taxi and half an hour later they arrived at our town, but it was two in the night. The young man was hungry and thirsty. He wished to get home as soon as possible. Something was wrong with the lift, so he had to go up the stairs. He stopped by my door and brought out a key. Of course he could not open the door. Half an hour passed but he failed. He became angry and shouted, “I’ll cut you down with a knife!”

The noise woke me up and I opened the door. I understood at once what was happening and said, “You’re trying to open a wrong door, Paul!”

“Sorry, I can’t agree with you, Charlie!” said the young man, “It’s my room. You’ve entered it by mistake!”

小题1: Paul and his friends enjoyed themselves on the island because ______.

A.It was very quiet there

B.there were many fish there

C.they could forget all the trouble

D.they could do what they wanted小题2: Paul couldn’t open the door because ______.

A.it wasn’t his room

B.he couldn’t find the right key

C.he didn’t find the keyhole

D.he was too hungry to do it小题3:Charlie opened the door to ______.

A.help Paul

B.stop Paul making the noise

C.see what happened outside

D.call the police station小题4:Which of the following is WRONG?

A.Paul thought he did right.

B.Paul didn’t know where he lived.

C.Paul stopped by a door on the fifth floor.

D.Paul thought he had reached the sixth

单项选择题