销售费用的通常测算方法是通过（ ）乘以一定比率来测算的
A．售价
B．土地取得成本
C．费用
D．利润
参考答案：A
It often happens that people with good eyesight fail to see is right in front of them.
A．which
B．that
C．what
D．as
GPRS与GSM的根本区别：GSM语音系统是一种分组交换系统，GPRS是一种电路交换系统。（）
