题干
The TV is too loud. Could you please ________?
A：turn it on
B：turn it up
C：turn it down
D：turn down it
答案(点此获取答案解析）
C
The TV is too loud. Could you please ________?
A：turn it on
B：turn it up
C：turn it down
D：turn down it
的导函数图象如图所示，则下面判断正确的是