he referred to in his article was often discussed by many people.
A. That
B. What
C. Whether
D. Where
网友回答
A. That
(答案→)B. What
C. Whether
D. Where
解析：考查主语从句。本题中的what引导主语从句what he referred to in his article并在句中作为refer to的宾语。句意：在他的文章中提到的事情经常被很多人讨论。That引导主语从句，只起引导作用，不能充当任何成分。Whether ,where不能在句中做主语或者宾语。故B正确。