Windows突破了DOS对常规内存（）RAM的限制。
A.360KB
B.512KB
C.640KB
D.1MB
参考答案：C
It was April 29,2011 _______ prince William and Kate Middleton walked into the palace hall
of the wedding ceremony.[ ]
A. that
B. when
C. since
D. before
某企业拟以“2/10，n/40”的信用条件购入一批货物，则放弃现金折扣的机会成本为( )。
A．2%
B．14.69%
C．18.37%
D．24.49%
