题干

随着世界经济的快速增长,对能源的需求也越来越大,核能作为清洁的能源,对于缓解能源紧张局面,减轻环境污染具有积极作用。已知某种核原料的原子核含有1个质子,2个中子,那么(    )

A:由该原子核形成的单质的相对质量为6

B:该元素是金属元素

C:该原子核外有3个电子

D:该原子核带2个单位的正电荷

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答案(点此获取答案解析)

A

同类题5

阅读短文,从短文下面的方框中的六个句子中选择五个还原到短文中,使短文通顺完整、衔接自然。

What’s in a Name?

    Your name is very important. When you think of yourself, you probably think of your name first. ____

    Right now, the two most popular names for babies in the United States are “Jacob” for boys and “Emily” for girls. ____ And why are some name unpopular?

    Names can become popular because of famous actors, TV or book heroes, or top players. Popular names mean very positive(积极的) things. Unpopular names mean negative(消极的) things. ____ Here are some common opinions about names from a recent survey.

Boys' names                           Girls' name

George: average, boring                  Betty: old-fashioned, average

Jacob: creative, friendly                  Emily: independent, adventurous

Michael: good-looking, athletic            Jane: common, ordinary

Stanley: out of date, serious               Nicole: beautiful, intelligent

____ The biggest reason is tradition. They have no choice. Many people are named after a family member.

____ A name that is unpopular now might become popular in the future. That's good news for all the Georges and Bettys out there.

A. Chinese names are different from English names.

B. Of course, opinions can change over times.

C. Surprisingly, people usually have similar opinions about names.

D. Why are these names popular?

E. Because it is an important part of your identity (身份).

F. So why do parents give their children unpopular names?