Now that there are still some problems remaining , we have to work extra hours tonight.
A. solved
B. solving
C. to be solved
D. to solve
网友回答
A. solved
B. solving
(答案→)C. to be solved
D. to solve
解析：考查remain的用法:句意：现在还有很多问题有待去解决，我们今晚要加班了。Remain to be done有待去做，选C。