--- 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.
A. worked
B. had worked
C. are working
D. had been working
网友回答
A. worked
B. had worked
(答案→)C. are working
D. had been working
解析：考查动词时态。语境意义：“这个问题还没解决，我们正在努力解决这个问题”，因此用现在进行时。对动词时态的考查历来是高考试卷的重点内容。