The problem ________ this material can be used in our factory has been solved. A．that B．what C．wheth...
2023-01-02 18:00:33 35次 2013届山东省临沂市高二下学期质量检测英语试试卷（解析版） 单项填空 反馈错误 加入收藏 正确率 : 100%
题目内容：
The problem ________ this material can be
used in our factory has been solved.
|
A．that
|
B．what
|
C．whether
|
D．why
|
本题链接：
