问题补充:
This is one of the problems at the meeting at present.
A. discussed
B. discussing
C. to be discussing
D. being discussed
答案:
A. discussed
B. discussing
C. to be discussing
(答案→)D. being discussed
解析:考查分词用法。根据后面的at present目前,现在;可知是指正在发生的动作。根据句意可知问题正在被讨论。句意:这是一个在现在的会议上正在被讨论的问题之一。