挑战习题
1/4单选题
难度:

1.

已知函数在区间[-1,3]上是减函数,则b的最小值是(     )


A

1

B

2

C

3

D

4

提示1:
PHA+5rGC5a+85pWw77yM5YeP5Ye95pWw5a+55bqU5a+85pWw5YC85bCP5LqO562J5LqOMDwvcD4=
正确答案:Qw==
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