The reason Tom came to attend the meeting was he was an expert in this field.
A. why; that
B. why; whether
C. that; why
D. why; because
网友回答
(答案→)A. why; that
B. why; whether
C. that; why
D. why; because
解析：句意：汤姆来参加会议的原因是他是这个领域的专家。第一空是定语从句的关系词，因为先行词是the reason，定语从句中不缺主宾表，缺少的是原因状语，所以用why引导定语从句，第二空是表语从句的连接词，主语是the reason的时候，表语从句用that连接，所以选A。