Is this the reason at the meeting for his carelessness in his work?A. he explainedB. wh

问题补充：

Is this the reason at the meeting for his carelessness in his work?

A. he explained

B. what he explained

C. how he explained

D. why he explained

答案：

(答案→)A. he explained

B. what he explained

C. how he explained

D. why he explained

解析：空白处引导定语从句，先行词是reason，因B、C两项不能引导定语从句，应排除。D项有一定干扰性，因先行词为the reason，但是，从句中缺少的是explained的宾语，不用why引导，应用which或that或省略。