—Is there any possible way to help them get rid of such a bad habit?—To tell the truth, it’s very hard. But we ________ on this problem, trying to improve the situation .
#101218
A
worked
B
had worked
C
are working
D
had been working
推荐题目
 --- So what is the procedure?--- All the applicants   before a final decision is made by the authority. 
#100604
A
interview
B
are interviewing
C
are interviewed
D
are being interviewed
The new method Mr.Wang has been devoted to _____ effective.
#101806
A
is proved
B
to prove
C
being proved
D
proves
Getting to the cinema, quite out of breath, we found the film     for ten minutes. 
#102720
A
having been on
B
had begun
C
had been on
D
had been started