问题
选择题
There are three ________ students in their school.
A．thousands of
B． thousand of
C． thousands
D． thousand
答案
答案：D
考查数词的用法。hundred/thousand/million/billion等前面有具体数字时，不能用复数形式，且不与of连用；hundred/thousand/million/billion单独使用，表虚数时，常用复数形式，且可以与of连用。根据three排除A、B、C。故选D。