He saw her ing, and advised me to hide behind the door, advice I took at once.
A. whose
B. what
C. that
D. which
网友回答
A. whose
B. what
C. that
(答案→)D. which
解析：考查非限制性定语从句。根据逗号可知，是非限制性定语从句，不能用that引导，what不能引导定语从句，排除B、C；which作主语或宾语，whose作定语。从句含有名词advice，应该用whose。故选D。