求 一道英语选择题,谢
问题描述：
求 一道英语选择题,谢
_________ people all over the world take part in the activity to save energy .
a.Millions of b.Million of c.Five millions D.Million
答
A
million,hundred,billion,thousand 这几个词前面有数词的时候不能加S,如果和of连用的时候就要S