问题
选择题
——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.
A．worked
B．had worked
C．are working
D．had been working
答案
答案：C
考查时态。“有帮助他们改掉这种坏习惯的可行的方法吗？”“说实话，非常难。但是我们还正在研究这个问题。”根据句意可知，用现在进行时。故选C。