如何保存视图中调板位置和可视状态。
参考答案：
菜单窗口-工作区-存储工作区命令。
设函数y=acosx+b（a、b为常数）的最大值是1，最小值是-7，那么acosx+bsinx的最大值是 ______．
(2013·山西高三诊断)Honey, you ________ alcohol for they have stopped drinking.
A．may not have bought
B．mustn't have bought
C．can't have bought
D．needn't have bought
