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.
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
正确答案是C
扫描二维码免费使用微信小程序搜题/刷题/查看解析。
版权声明：本文由翰林刷题小程序授权发布，如需转载请注明出处。