Although there is no life on Mars now , some scientists think that there some form of life

发布时间：2020-08-16 10:13:55

Although there is no life on Mars now , some scientists think that there      some form of life a long time ago .
A. must be
B. may have been
C. can have been
D. could be

网友回答

A. must be
(答案→)B. may have been
C. can have been
D. could be
解析：可联系答.案.网客服索取。
以上问题属网友观点，不代表本站立场，仅供参考！