精英家教网 > 高中英语 > 题目详情

10、Such a problem exists because measures for preventing it _______ taken in the past.

A.is not          B.has not         C.were not           D.had not

10、C

请在这里输入关键词:
相关习题

科目:高中英语 来源: 题型:

Such a problem exists because measures for preventing it _______ taken in the past.

A.is not          B.has not         C.were not           D.had not

查看答案和解析>>


同步练习册答案