题目内容

地球高层大气的分子和原子,在()的作用下发生电离。

查看答案
更多问题

电离层各种粒子成分随高度统一变化。

A. 对
B. 错

TEC指的是什么?

The promulgation of joint venturelaws paves a way foreign businessmen to invest in China.

A. To
B.for
C. by
D. with

We are confident that you willfind _____ ready market for the item _____ your end.

A. /, at
B. a,by
C. a, at
D.some, by

答案查题题库