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
The person we talked about ____ our school last week．
#104467
A
visiting
B
will visit
C
visited
D
has visited
–Excuse me, sir, didn’t you see the red light?–Sorry, my mind ________ somewhere else.
#102792
A
has been wandering
B
was wandered
C
was wandering
D
has been wandered
—Have you ever been to Singapore?— Yes, I ____ there 3 times in 2009 alone.
#99248
A
have been
B
have gone
C
went
D
had gone
— Why do you look so worried? —My computer broke down and my essay ______ unfinished since.
#101403
A
had left
B
has been left
C
has left
D
was left