40w荧光灯镇流器功率因数损耗系数α为()。 ["0.20","0.26","0.10","0.15"]
新生儿体温调节功能差,体温的维持主要依靠() ["适宜的环境温度","棕色脂肪的产热作用","足够的母乳摄入","自发的肢体活动","汗腺发育差,散热少"]
在未办理工作票终结手续以前,值班员不准()。
根据被测电流的种类分为()。 ["A、直流","B、交直流","C、以上都是","D、交流"]
肉苁蓉的原植物科名是() ["A.豆科","B.桑寄生科","C.列当科","D.小檗科","E.兰科"]
电子汇兑系统特点及分类?