So far no life has been found outside the earth, but while some scientists are actively searching for living things in outer space, others firmly believe there ____ .
A.mustn’t be | B.may not be | C.can’t be | D.won’t be |
推荐套卷
So far no life has been found outside the earth, but while some scientists are actively searching for living things in outer space, others firmly believe there ____ .
A.mustn’t be | B.may not be | C.can’t be | D.won’t be |