题目内容：

The number of the students ___.
A.is getting bigger and bigger
B.are getting bigger and bigger
C.is getting more and more
D.are getting more and more

优质解答

the number of 是……的数目的意思,谓语用单数,主语是number
a number of 是许多谓语用复数,主语是of 后面的成分
number 一般用large或者big
综上所述,选择A