问题 单项选择题 A1型题

核医学显像的放射性核素应达到的要求中下列哪项错误()。

A.相对短半衰期,但持续时间够临床检查

B.α、β和γ射线均可

C.不发射γ射线的能量足够能在患者体外检测到

D.不发射检查无效的太高能γ射线

E.达到最大可能的比活度,避免对患者的任何毒性效应

答案

参考答案:B

解析:无α射线或β射线,单能γ射线最理想。

单项选择题
阅读理解

People need to relax and enjoy themse1ves.One way they can have a good time is to watch a baseball game or another sports event.Even thousands of years ago,groups of people gathered to watch skilled athletes(运动员).

  Over 2000 years ago in Greece,certain days in the year were festival days.These were holidays when people stopped work and enjoyed themselves.They liked to watch athletes take part in  races and other games of skill.

The most important festival was held every four years at the town of Olympia.It was held in honor of the Greek God Zeus(Zus).For five days,athletes from all parts of the Greek world took part in the Olympic Games.At the Olympic Games,people could watch them box(拳击),run,jump and so on.There was a relay race between two teams of men in which a lighted torch(火矩)was passed from runner to runner.The Olympic Games were thought to be so important that cities which were at war with one another had to stop fighting.Just then people were allowed to travel to the games safely.Thousands of people came to Olympia from cities in Greece and from her colonies(殖民地)in Africa,Asia and Italy.They met as friends to cheer their favorite athletes and to enjoy themselves.

小题1:What happened in Greece over 2000 years ago?

A.People needn’t to work.

B.There were often against one another in cities.

C.People watched baseball games.

D.People didn’t go to any games at all.小题2:What were those countries in Africa?

A.Friends.

B.Enemies.

C.Colonies.

D.Relatives.小题3:What did people do at the games?

A.They fought.

B.They just talked to friends.

C.They cheered for their favorite athletes

D.They tried to find friends.小题4:Greek cities then were fighting so they_____.

A.were weak

B.were safe

C.couldn’t go to other cities freely

D.could see each other小题5:The best title for the story is“_____”.

A.Greece at War

B.To gather for the Games

C.Stop Fighting

D.Sport