To tell you the truth, it's very hard for us to help them get ri

To tell you the truth, it's very hard for us to help them get rid of Internet addiction. But we _________ on this problem trying to improve the situation.
A、worked
B、had worked
C、are working
D、had been working
【正确答案】：C
【题目解析】：【答案】C 【译文】说实话，帮助他们戒除网瘾很困难，但是我们正在努力解决这个问题。 【考点】动词时态 【解析】根据语境意义，我们可知这个动作正在进行中，因此用现在进行时。