在S7-200系列PLC中，使用PPI电缆编程通讯是可以设置的波特率为（） A.1.

— Which of these two magazines will you take?

— I'll take ____, in case the journey is boring. [ ]

A. all

B. either

C. both

D. neither

下列数据中最接近生活实际的是[ ]

A．家用电冰箱的额定电流约为5A

B．家用空调机的功率约为1000W

C．家用节能灯的额定功率约为500W

D．人体的安全电压不高于220V

中风的基本病机是（）

A.心火上炎

B.肝肾阴虚

C.脾失健运

D.气血逆乱

E.阴阳失调

A discount retailer of basic household necessities employs thousands of people and pays most of them at the minimum wage rate. Yet following a federally mandated increase of the minimum wage rate that increased the retailer’s operating costs considerably, the retailer’s profits increased markedly.
Which of the following, if true, most helps to resolve the apparent paradox

A．Over half of the retailer’s operating costs consist of payroll expenditures; yet only a small percentage of those expenditures go to pay management salaries.

B．The retailer’s customer base is made up primarily of people who earn, or who depend on the earnings of others who earn the minimum wage.

C．The retailer’s operating costs, other than wages, increased substantially after the increase in the minimum wage rate went into effect.

D．When the increase in the minimum wage rate went into effect, the retailer also raised the wage rate for employees who had been earning just above minimum wage.

E．(E) The majority of the retailer’s employees work as cashiers, and most cashiers are paid the minimum wage.

网络系统的（）应考虑：网络的分布、网络的基本设备和类型、网络的基本规模和网络的基本功能和服务项目等问题。