When and where this took place _____ still unknown.
#85610
A
is
B
has
C
were
D
are
推荐题目
—He is the only one of the students ______from the country in my class, and we have known for quite some time.—Where did you meet for the first time? —It was on the farm ________ I used to work.
#85623
A
who are; that
B
who is; where
C
that is; that
D
whom are; on which
The number of people invited to the conference _____ 150,but a number of them ______ absent for different reasons.
#86222
A
were;was
B
were;were
C
was;were
D
was;was
E-mail, as well as telephones, _____ an important part in daily communication.
#85691
A
is playing
B
have played
C
are playing
D
played
Every possible means ______ to prevent the air pollution, but the sky is still not clear.
#85598
A
has been used
B
have been used
C
is used
D
are used