The number of smokers in China increased in recent years and a number of them the youth

问题补充：

The number of smokers in China increased in recent years, and a number of them the youth.

A. has; are

B. have; are

C. is; is

D. are; are

答案：

(答案→)A. has; are

B. have; are

C. is; is

D. are; are

解析：句意：最近几年，中国的吸烟的人的数量增加了，他们中的许多人都是年轻人。The number of…的数量，谓语动词用单数；a number of = many，许多的意思，谓语动词用复数，选A。