The number of foreign students attending Chinese universities rising steadily since .A

问题补充：

The number of foreign students attending Chinese universities rising steadily since .

A. is

B. are

C. has been

D. have been

答案：

A. is

B. are

(答案→)C. has been

D. have been

解析：句意：自从开始来上中国大学的外国学生的数量一直在增长。因为与since当“自从”讲，常与现在完成时连用。因为整个句子的主语是number，它作主语时谓语动词用单数，故选C。