【题目】The reason ________ he explained was________ he was ill and unable to go to school.
A.why; thatB.why; becauseC.which; becauseD.which; that
在线课程【答案】D
【解析】
考查定语从句和表语从句。句意：他解释的原因是他生病了不能去上学。本句中先行词the reason是定语从句he explained的宾语，指物，引导词用which或者that，系动词was后是表语从句，句子中不缺少句子成分，用that作引导词。故选D。