—Were you busy last weekend?

—Very. Rather than ____ time playing cards as usual, I devoted every effort to ____ an advertisement.

A．wasting; making

B．waste; make

C．to waste; make

D．a waste of; making

使用FORMATC：/S格式化系统后，C盘上的DOS系统文件包括：IO.SYS；（）；COMMAND.COM