“输入掩码”用于设定控件的输入格式，对什么数据有效
A．数字型
B．货币型
C．日期型
D．备注型
参考答案：C
There's a _____ in our office that when it's somebody's birthday, they bring in a cake for us all to share. [ ]
A. tradition
B. balance
C. concern
D. relationship
下列现象属于凝华的是[ ]
A．冬季黄河水结冰
B．露
C．霜
D．雾
