位置:首页 > 题库频道 > 学历类 > 升学考试 > 高中(高考) > 英语 > 高考英语虚拟语气练习271

Although there is no life on Mars now , some scientists think that there ______ some form of life a long time ago .

发布时间:2021-08-10

A.must be

B.may have been

C.can have been

D.could be

试卷相关题目

返回顶部