采集种公猪精液的方法一般为()
A.假 * * 法
B.手握法
C.电刺激法
D.按摩法
参考答案:B
The twins are so much alike that it is difficult to tell one from________.
A.other
B.the other
C.others
D.another
医院的医疗器械的电气设备可选用动作电流为()以内动作的漏电保护器。
A、30mA,0.1S
B、15mA,0.1S
C、6mA,0.1S
D、50mA,0.1S