为了区别“数字”与“数字字符串”数据，Excel要求再输入项前添加________符号。
A．"
B．’
C． #
D．@
参考答案：B
改错。
( ) 1. Mr. Smith is wash the dirty dishes. ________________
A B C D
( ) 2. What would you like breakfast? ________________
( ) 3. Li Ming plane arrived at 5: 00. ________________
( ) 4. Everyone in the living room are quiet. ________________
半变动成本
