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。
