--- What’s the matter, Mary? You looked upset.
--- I failed again in my math exam. I’m really sorry because I don’t want to my parents down.
A. turn
B. write
C. let
D. take
网友回答
A. turn
B. write
(答案→)C. let
D. take
解析：turn转动，转变；write写；let让；take带走，拿。句意：怎么了？玛丽。你看起来很沮丧。——我在数学考试中又不及格。我真的很抱歉，因为我不想让我的父母失望。短语let sb down让某人失望，故选C。