问题 选择题

X元素原子的质量数为m,核内中子数为n,则Wg X2+ 离子含有的电子的物质的量约为(  )

A.mol

B.mol

C.mol

D.mol

答案

答案:D

X元素的原子序数是m-n,则X2+ 离子的电子数是m-n-2。所以Wg X2+ 离子含有的电子的物质的量,所以答案是D。

听力题

根据首字母,中文或括号里词的适当形式填写单词。只限填Module 6 Unit 2-Unit 5的单词。(共10小题;每小题1分,满分10分)

小题1:This book was a_______ (合适地) written in a style accepted by teenagers, who enjoy reading it.

小题2:I keep getting c_______ (矛盾的) advice — some people tell me to keep it warm and some tell me to put ice on it. 

小题3:To make matters worse, some adolescents are so a_______ to computer games that too much time and energy are wasted.

小题4:The little boy was _______ (embarrass) when his mother, who had a severe scar on her face, attended his first teacher-parent conference.

小题5:Both children have _______ (normal) high levels of infectious virus in their blood.

小题6:To g_______ (确保, 保证) the policy could be effective, the local government took measures to carry out lots of detailed related plans to support the policy.

小题7:E-mail _______ (transform) the way people communicate in the past few years, which makes people feel it convenient to keep in touch with each other.

小题8:You see, during adolescence I also smoked a lot, but after I know smoking damages health, I stopped smoking by _______ (strong) my resolve.

小题9:Some people are in favor of the policy. They think it is reasonable and fair to carry out the policy, because the more the oil _______ (consume) is, the more money the drivers pay, which can avoid the unnecessary driving.

小题10:Joyfully, the elderly _______ (present) with flowers, fruits and presents on that day.

单项选择题