The number of the students in our school rising since .A. is B. has been C. are D. ha

问题补充：

The number of the students in our school rising since .

A. is

B. has been

C. are

D. have been

答案：

A. is

(答案→)B. has been

C. are

D. have been

解析：the number of……的数目，修饰名词，谓语动词用单数；再根据时间状语since 可知用现在完成时。句意：自从，我们学校学生的数目一直在增长。