Is this the reason at the meeting for his carelessness in his work?
A. explained
B. what he explained
C. how he explained
D. why he explained
网友回答
(答案→)A. explained
B. what he explained
C. how he explained
D. why he explained
解析：句意：这就是那个他在会议上解释的由于工作粗心的原因吗？explained at the meeting for his carelessness in his work这是定语，修饰the reason，它与explain之间是被动关系，故用过去分词。如果用定语从句必须用关系代词做explain的宾语，用that或which都行。故选A。