放射性核素的选择原则不包括() A.高比活度 B.容易标记 C.适宜半衰期 D.标记

题型:单项选择题

问题:

放射性核素的选择原则不包括()

A.高比活度

B.容易标记

C.适宜半衰期

D.标记物易于保存

E.对抗原或抗体活性没有影响

考点:临床医学检验临床化学技术临床免疫学检验临床免疫学检验题库
题型:单项选择题

About 21,000 young people in 17 American states do not attend classes in school buildings.

Instead, they receive their elementary and high school education by working at home on computers. The center for Education Reform says the United States has 67 public “cyberschools(网络学校)” and that is about twice as many as two years ago.

The money for students to go to a cyberschool comes from the governments of the states where they live. Some educators say cyberschools receive money that should support traditional public schools. They also say it is difficult to know if students are learning well.

Other educators praise this new form of education for letting students work at their own speed. These people say cyberschools help students who were unhappy or unsuccessful in traditional schools. They say learning at home by computer ends long bus rides for children who live far from school.

Whatever the judgment of cyberschools, they are getting more and more popular. For example, a new cyberschools called Commonwealth Connections Academy will take in students this fall. It will serve children in the state of Pennsylvania from ages five through thirteen.

Children get free equipment for their online education. This includes a computer, a printer, books and technical services. Parents and students talk with teachers by telephone or by sending emails through their computers when necessary.

Students at cyberschools usually do not know one another. But 56 such students finished studies at Western Pennsylvania Cyber Charter School recently met for the first time. They were guests of honor at their graduation.

小题1:What do we know from the text about students of a cyberschools?

A.They have to take long bus rides to school.

B.They study at home rather than in classrooms.

C.They receive money from traditional public schools.

D.They do well in traditional school programs.小题2:What is a problem with cyberschools?

A.Their equipment costs a lot of money.

B.They get little support from the state government.

C.It is hard to know students' progress in learning.

D.The students find it hard to make friends.小题3:Cyberschools are getting popular because__________.

A.they are less expensive for students

B.their students can work at their own speed

C.their graduates are more successful in society

D.they serve students in a wider age range

题型:单项选择题

一氧化碳中毒的机制,描述正确的是()。

A.HbCO的解离较氧合血红蛋白的解离速度快3600倍

B.氧合血红蛋白的解离较HbCO的解离速度快240倍

C.O2与血红蛋白亲和力比CO与血红蛋白亲和力大3600倍

D.CO与血红蛋白亲和力比O2与血红蛋白亲和力大240倍

E.O2与血红蛋白亲和力比CO与血红蛋白亲和力大240倍

题型:单项选择题

对于心悸患者的活动量不正确的是

A.均应卧床休息

B.均不需卧床休息

C.轻证可以进行适当的体力活动

D.活动量以不觉疲劳,不加重症状为度

E.重症患者,待症状消失后,即可活动

题型:单项选择题

建筑物基础埋深指的是( )。

A.从±0.00到基础底面的垂直距离

B.从室外地面到基础底面垂直距离

C.从室外设计地面到垫层底面的垂直距离

D.从室外设计地面到基础底面的垂直距离

题型:单项选择题

已知函数f(x)=ax3-bx2+cx在区间(-∞,+∞)内是奇函数,且当 x=1时f(x)有极小值

,求a,b,c.

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