By the middle of the 21st century ,the vast majority of the world's population _ in the cities rather than in the countr
问题描述：
By the middle of the 21st century ,the vast majority of the world's population _ in the cities rather than in the country.
A.are living B.will be living C.have lived D.will have lived
答
答案：B
解释：
1、由于时间状语是将来的,所以用一般将来时,排除C.
2、答案A are要改成 is,所以A 排除.
3、will have lived 表示“将已经居住在”,是完成时.
4、will be living 用的是一般将来时的进行时.
祝你新年快乐,学习更上一层楼!请记得采纳,谢谢!(*^__^*)