When deeply absorbed in work， he often was，he would forget all about eating or sleeping. (2012·北京，26)
A. that
B. which
C. where
D. when
网友回答
A. that
B. which
C. where
D. when
解析：B
解析 句意为：当他全身心地投入工作中时，他就会废寝忘食，而他经常这样(全身心地投入工作)。由引导词前面的逗号可知，这是一个非限制性定语从句，所以首先排除that。由定语从句的was可知，定语从句缺少表语，所以排除在定语从句中作状语的where和when。故选B项。