Thereason hewaslateforschoolwas

The reason he was late for school was he had to send his mother to a hospital.A.which; thatB.why; thatC.for which; becauseD.what; why

B解析试题分析：考查定语从句和表语从句。本题第一空是由why引导的是定语从句，修饰名词the reason，后面定语从句的句子结构很完整，所以使用关系副词。第二空是that所引导的表语从句，that在句中不充当任何成分，只起引导和连接的作用。句意：他上学迟到的原因是他要送妈妈去医院。故B正确。考点：考查定语从句和表语从句点评：连接表语从句的连接词有：that, what, who, when, where, which, why, whether, how, whoever，whomever，whichever ，whatever等。还有如because, as if, as though等。解答这类题目，关键在于分析清楚句子结构。通过判断引导词在从句中所作的成分及意义，来选择正确的引导词。定语从句的考查主要就是考查关系词的辨析，关系代词that, which, whose, whom, as， who在句中做主语，宾语，表语或者定语；where, why, when在句中做状语。要分析句子成分，看缺少什么成分，就选用相应的关系词。

这个问题的回答的对