电能表按其工作原理可分为（）电能表。
A.机械式和电子式
B.交流和直流
C.整体式和分体式
D.普通安装式和携带式精密级
参考答案：A
___________two tickets for the new play at the Grand Theatre on Saturday. Shall we go and see it together?
A．They have been given
B．I have been given
C．I am given
D．They have given to me
房间隔缺损分流量大小与下面哪些因素有关()
A．肺小动脉阻力
B．两侧心房压力差
C．缺损大小
D．心房的顺应性
E．心室的顺应性
