题干
--They were ________ busy ________ with each other ________ the time.
--- How cool the guys are !
--- How cool the guys are !
A：too; to talk; to forget
B：too; talking; to forget
C：so; to talk; that they forgot
D：so; talking; that they forgot
答案(点此获取答案解析）
D
在区间
上是减函数，那么
有（ ）