f(x)=A、RB、[4, ∞)C、[4, ∞)∪(-∞,0]D、(-∞,0] f(x)=A、RB、[4, ∞)C、[4, ∞)∪(-∞,0]D、(-∞,0] 发布时间:2025-08-09 22:47:13