在EXCEL2003中，工作薄文件的扩展名是（）。
A.xlw
B.Xlt
C.xls
D.xlc
参考答案：C
—Don't shout in the library, please.
—________[ ]
A. It doesn't matter.
B. That's all right.
C. Sorry, I won't.
D. Excuse me.
