3.5英寸软盘的移动滑块从写保护窗口上移开，此时（）。
A.写保护
B.读保护
C.读写保护
D.驱动器定位
参考答案：A
—Do you think it will do us good or harm?
— ________. Let's beg for God's help. [ ]
A. It's hard to say
B. I'm sure
C. It's impossible
D. You are right
如果直线a∥b，且直线c⊥a，则直线c与b的位置关系( )（填“平行”或“垂直”）．
