带电粒子与原子的相互作用中,传递给轨道电子的能量不足以使原子电离,相互作用的结果是轨

题型:单项选择题

问题:

带电粒子与原子的相互作用中,传递给轨道电子的能量不足以使原子电离,相互作用的结果是轨道电子运动到更高的壳层,这个过程被称为()。

A.湮灭辐射

B.激发

C.电离

D.次电离

E.原电离

考点:核医学与技术(医学高级)核医学与技术仿真试题二
题型:单项选择题

     根据对话内容,从对话后的选项中选出能填入空白处的最佳选项,选项中有两项多

余选项。

— How often do you use he Internet?

  1 But I usually use it o check my email. I don't often surf the Internet. You use the Internet a lot,

    don't you?

—   2  

— So, you're working online eight hours a day. It can be awful when the connection is poor.

—   3 Sometimes I also help others in the office if they're having trouble online.

— How useful do you think the Internet is as a source of information?

— I think it's useful.    4   The information online may be false. You don't see what you buy online

      until you actually get it.

—   5    

— We usually find the website of shops, then visit the shop and buy when we've seen the products.

A. But there are two big problems.

B. Yes. I usually surf the Internet to look through the news.

C. Why do you want to buy something online?

D. Yes. I use it to find products at the lowest price for my company.

E. Yes. I like the job though.

F. How do you solve the problems when shopping online?

G. I use it almost everyday.

题型:单项选择题

葡萄球菌蛋白A(SPA)可激发转化增殖的是 ()

A.B细胞

B.T细胞

C.NK细胞

D.粒细胞

E.巨噬细胞

题型:单项选择题

实验方法的运用,才使得生物学进入_________的行列。

题型:单项选择题

Don't just stand there. Do _______! [ ]

A. anything

B. something

C. everything

D. nothing

题型:单项选择题

对一个关系投影操作以后,新关系的元组个数与原来关系的元组个数的关系是

A.小于

B.大于等于

C.等于

D.大于

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