( )是以信用活动为基础产生的，能够发挥货币作用的信用工具。
A．信用货币
B．电子货币
C．实物货币
D．表征货币
参考答案：A
—Can you let me know _____ yesterday?
—Because the traffic was bad. [ ]
A. why did you come late
B. why you came late
C. why do you come late
D. why you come late
磁盘格式化时，被划分为一定数量的同心圆磁道，软盘上最外圈的磁道是
A) 0磁道 B) 39磁道C) 1磁道 D) 80磁道
