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
--Have you seen Tony recently? --No, but I ________ dinner with him on Sunday．
#103008
A
would have
B
have had
C
have been having
D
am having
His invention ______ of no use by the scientists of that time．
#103132
A
considered being
B
considered to be
C
was considered to be
D
was considered being
Don’t call me tomorrow evening, for I ____________to a lecture on how to keep a good state of mind when taking an exam.
#101334
A
will listen
B
should listen
C
shall listen
D
will be listening
If you __________ me, I will give you some advice.
#104458
A
listen to
B
will listen to
C
listen
D
are listening
In such dry weather, the flowers will have to be watered if they ____________
#104811
A
have survived
B
are to survive
C
would survive
D
will survive