题干
I strongly recommend that the information______ in my report ____ to our headmaster without delay.
A：to be referred to; to be e-mailed
B：referring to; e-mail
C：referred to; be e-mailed
D：being referred to; being e-mailed
答案(点此获取答案解析）
C
，且其图像关于 
轴对称，则函数 
的一个单调递减区间是（ ）
