More than twenty students are having an important exam at the moment.
A. thousands
B. thousands of
C. thousand
D. thousand of
网友回答
A. thousands
B. thousands of
(答案→)C. thousand
D. thousand of
解析：thousand 表示千时，无论表示几千，thousand 后都不加s，而thousands of，表示成千上万的，故选C