the number of foreign students attending chinese universities ———— rising stesding since 1997

题目

the number of foreign students attending chinese universities ———— rising stesding since 1997
为什么用has been

答案

根据since 1997可以看出要用现在完成时态.
the number of ...意思是“……的数目”,后面的动词要用单数第三人称