问题
选择题
When deeply lost in thought, _______ he often was, he would forget all about eating or sleeping.
A.that
B.where
C.which
D.when
答案
答案:C
题目分析:考查定语从句。由结构判断此处是定语从句,从句缺少表语,用关系代词,故排除B、D选项, 而that不引导非限制性定语从句,所以答案选C。句意:当他陷入沉思中时,他总会忘记吃饭、睡觉,这种情况时常发生。