Question

Since three months ago, the number of students making notes while listening in class ________ 90％．

[　　]

A．

has increased by

B．

was increased to

C．

have increased for

D．

had increased by

Answer 1

答案：A
解析：

since three months ago是现在完成时的时间状语，所以句子的时态要用现在完成时。increase by 意思是“增长了多少”，而increase to为“增长到(一个具体的数字)”。the number of students意思是“学生的数目”，谓语动词应该用单数形式。