There are about students in their school now..A. hundred ofB. nine hundredC. nine hundred

问题补充：

There are about students in their school now..

A. hundred of

B. nine hundred

C. nine hundreds

D. nine hundreds of

答案：

A. hundred of

(答案→)B. nine hundred

C. nine hundreds

D. nine hundreds of

解析：英语中数词表示概数时，后面加s，和介词of搭配使用。用原形时表示具体数字和数词搭配使用。句意;现在他们的学校大约有九百学生.结合语境可知本句中描述的是具体的数字,故选B.