从电网送到企业的电能线损率要求:一次变压不得超过()。 ["2.5%","3.5%","5.5%","7%"]
上述镇静、抗惊厥作用的药物,错误的是() ["A.天麻","B.地龙","C.钩藤","D.麻黄","E.蜈蚣"]
洋地黄中毒引起室速,治疗首选() ["苯妥英钠","利多卡因","安装人工心脏起搏器","非同步直流电复律术","同步直流电复律术"]
数码相机的快门时滞很大,接近()。 ["0.1秒","2秒","1秒","0.2秒"]
持续性房颤药物转复无效时,可以采取() ["苯妥英钠","利多卡因","安装人工心脏起搏器","非同步直流电复律术","同步直流电复律术"]
海洋空间资源包括哪些?