Migration is the dynamic ______ of population's change:everyone's

solution,everyone's conflict.

A. undertaking     B. underwater    C. undertow    D.underweight

上期习题答案：

The central provinces have floods in some years, and ____________.


A. drought in others    B. droughts are others  C. while others droughts   D. others in drought

中部省份一些年里会有水灾，而其他年份则为干旱。

答案：A

本句是一个并列句，因此连词and后相同的谓语词have被省略了。