Space exploration began in the 1960s, and since then about five hundred people into space.
#101989
A
have traveled
B
traveled
C
had traveled
D
are traveling
推荐题目
Sorry to have kept you waiting. You must have thought ___.
#99981
A
we are not coming
B
we were not coming
C
we did not come
D
we were not come
A new cinema _______ here. They hope to finish it next month.
#101290
A
will be built
B
is built
C
has been built
D
is being built
The man whose songs we are fond of ____ in our city next week．
#104221
A
singing
B
to sing
C
will sing
D
sang
--- One of you will have to go there besides me. --- Who would you rather _____ there with you. Tom or I?
#103659
A
have to go
B
to go
C
went
D
go
Our TV sets sell well, but ten years ago no one could have imagined such a big share in the market that they ____.
#104699
A
were having
B
had had
C
were to have
D
had