题干
--- Why do you suggest we buy a new machine?
--- Because the old one has been damaged ___________.
--- Because the old one has been damaged ___________.
A：beyond reach
B：beyond repair
C：beyond control
D：beyond descriptio
答案(点此获取答案解析）
B
（
，
），满足
，
，且
的最小值等于
，则函数
的一个单调递增区间是（ ）
