抛物线y=-2x2+8x-8的对称轴是直线______．
∵y=-2x2+8x-8=-2（x-2）2，
∴抛物线的对称轴是直线x=2．
I thought you _____ like something to read, so I have brought you some books. [ ]
A. may
B. might
C. could
D. must
可以在异地使用的支付结算方式有哪些（）
A、汇兑
B、银行汇票
C、托收承付
D、委托收款
