题干
用图象法解方程组 x - 2 y = 4 2 x + y = 4
A：
B：
C：
D：
答案(点此获取答案解析）
C
在区间(－∞，4上是减函数，那么实数a的取值范围是（ ）
ter several years, she changed a lot and looked different from ____ she used to be.