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
推荐题目
Professor Smith, along with his assistants,______ on the project day and night to meet the deadline.
#86316
A
work
B
working
C
is working
D
are working
(2013·高考湖南卷)The university estimates that living expenses for international students________around $8,450 a year，which________a burden for some of them.
#85584
A
are；is
B
are；are
C
is；are
D
is；is
The number of people invited to the party ____ fifty, but a number of them ____ absent for different reasons.
#85712
A
were; was
B
was; was
C
was; were
D
were; were