肺动脉干()。 ["起自左心室","起自主动脉","在主动脉弓上方分为左右两支","其分叉处偏左侧与主动脉弓之间有动脉韧带","是体循环的主干"]
()为主变流器控制提供同步信号、为原边电压的检测和电度表的计量提供电压输入信号的电器。 ["TV1","TA1","TA2"]
钩端螺旋体病的传染源是() ["鸡鸭","野鼠","鸟类","蚊子","跳蚤"]
用户在装表接电前必须具备哪些条件?
对眼猪囊尾蚴病患者首选的治疗是() ["氯喹","吡喹酮","抗生素","伯氨喹","手术"]
水表安装时分别用铜管和套管与上下两个水表塞门连接,上方的塞门与锅炉容器空间连接称()。