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
——How long has his father ________London?——For two weeks.
#40461
A
been to
B
gone to
C
been in
D
arrived in
—Where have you _________ all day? —I came back at noon and I _________ in this room ever since.
#40192
A
gone; had been
B
gone; was
C
been; have been
D
been; am
---- Where is Mr. Green now? I haven’t seen him for a few days ---- He ________________ to Shanghai.
#42471
A
goes
B
will go
C
is going
D
has gone
—What do you often do at weekends?—I often _________ my grandparents.
#36326
A
visit
B
visited
C
have visited
D
will visit