题干
---- I’m very tired these days because of studying for exams.
-----Why not _____ music. It can make you _____.
-----Why not _____ music. It can make you _____.
A：listen to, relaxing
B：to listen to, relax
C：listening to, relax
D：listen to ,relax
答案(点此获取答案解析）
D
的导函数 
则函数 
的单调递减区间是（ ）