从飞机发电机或电瓶连接到汇流条的主电源线,使用时其压降不超过()
A.3%
B.2%
C.4%
参考答案:B
33.Bread and butter____________ for breakfast in many Chinese homes nowadays.
A.serve
B.servers
C.is served
D.are served
肺实变时触诊可出现
A.气管居中,语音震颤增强B.气管偏向健侧,语音震颤增强C.气管偏向患侧,语音震颤减弱D.气管偏向健侧,语音震颤减弱E.气管居中,语音震颤减弱