在Word中，单击工具栏中的______按钮可以在屏幕上预览显示打印效果。
参考答案：打印预览
投运密闭输油流程前，如何检查投运高低压泄压保护装置？
Ms Wright complained that her husband never asked about the price ___ he decided to buy musical disks.
A．while
B．before
C．after
D．as soon as
