The scientists ________ on the new medicine for two years. They will succeed in no time. 
#38384
A
work
B
are working
C
have worked
D
will work
推荐题目
Linda, with her parents,_______ the Wolf Hill, and they will be back this afternoon.
#42030
A
has gone to
B
have gone to
C
has been to
D
have been to
They______ when the teacher came in.
#40078
A
talk
B
are talking
C
to talk
D
were talking
There _______ two basketball matches on TV this evening.
#42009
A
are going to be
B
is going to
C
will have
D
are going to have