问题 单项选择题

关于CT机准备,错误的是()

A.扫描前,训练球管是起保护球管的作用

B.训练球管是从高千伏、高毫安到低千伏、低毫安进行多次曝光

C.训练球管是使一段时间不使用的冷却球管逐渐升温,避免突然过冷、过热的情况出现

D.CT值的校准,是对电器设备由于环境的变化在扫描时引起的误差所作的修正

E.CT值的校准又称"零点漂移校正"

答案

参考答案:B

解析:训练球管是从低千伏、低毫安到高千伏、高毫安进行多次曝光。

阅读理解

阅读理解。

     “Life is speeding up. Everyone is getting unwell.”

      This may sound like something someone would say today. But in fact, an unknown citizen who lived

in Rome in AD 52 wrote it.

     We all love new inventions. They are exciting, amazing and can even change our lives.

     But have all these developments really improve the quality of our lives?

     Picture this: You’re rushing to finish your homework on the computer. Your mobile phone rings, a

QQ message from your friend appears on the screen, the noise from the television is getting louder and

louder. Suddenly the computer goes blank and you lose all your work. Now you have to stay up all

night to get it done. How calm and happy do you feel?

     Inventions have speeded up our lives so much that they often leave us feeling stressed and tired.

Why do you think people who live far away from noisy cities, who have no telephones, no cars, not

even any electricity often seem to be happier? Perhaps because they lead simpler lives.

     One family in the UK went “back in time” to see what life was like without all the inventions we have

today. The grandparents, with their daughter, and grandsons Benjamin, 10, and Tomas, 7, spent nine

weeks in a 1940s house. They had no washing machine, microwave, computer or mobile phones.

     The grandmother, Lyn, said, “It was hard physically, but not mentally.” She believed life was less

materialistic. “The more things you have, the more difficult life becomes,” She said. The boys said they

fought less to fight over, such as their computer. Benjamin also noticed that his grandmother had

changed from being a “fashionable, beer-drinking granny, to one who cooked things.”

     Here are some simple ways to beat the stress often caused by our inventions!

     Don’t be available all the time. Turn off your mobile phone at certain times of the day. Don’t check

your e-mail every day.

     Don’t reply to somebody as soon as they leave a text message just because you can. It may be fun

at first, but it soon gets annoying.

1.The passage is mainly about        .

A.problems with technology    

B.improvements of our life with technology

C.the important roles technology plays in our everyday life

D.major changes which will be likely to happen to technology

2.The writer quoted what a citizen in ancient Rome said at the beginning of the story in order to        .

A.share a truth about life      

B.tell us what life was like long time ago

C.make us wonder what causes such a thing to happen

D.point out that you experience some big problems and they may be

      the same

3.The family chose to spend some time in a 1940’s house because        .

A.they liked to live simple lives

B.they were curious about how people lived without modern inventions

C.they were troubled by modern inventions

D.living in a different time would be a lot of fun for them

4.What does the word “available” in the suggestion offered by the writer mean?

A.Busy on line

B.Free

C.Be able to

D.Be found by others.

单项选择题 B型题