无线网主要采用的技术有（）
A.微波通信
B.红外线通信
C.激光通信
D.以上都是
参考答案：D
Which of the following is the simplest way for a company to increase its reported operating cash flow（）
A. Record sales on a bill-and-hold basis.
B. Slow down the rate of payment to suppliers.
C. use a third party financial institution to pay suppliers.
可治疗久咳虚喘和心悸失眠多梦的药( )
A．山茱萸B．五味子C．五倍子D．莲子
