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
-Where’s your father?-He ______ Beijing. He won’t be back ______ next week.
#42185
A
has gone to; until
B
has been to; until
C
has been to; after
D
has gone to; after
---What ______ the forest of Yangzhou in the last 30 years?---Yangzhou has become much greener.
#39620
A
has happened to
B
was happened to
C
has happened at
D
is happening
My iphone 5 needs to be repaired. How much do you think it _____? 
#39258
A
would cost
B
cost
C
has cost
D
will cost