随地吐痰易传播() ["A、流脑","B、乙肝","C、艾滋病","D、肺结核"]
发电机出口PT的变比是多少()。 ["22/0.1;","21/0.1;","20/0.1;","19/0.1。"]
若从某一初态经可逆与不可逆两条途径到达同一终态,则不可逆途径的△S必()可逆过程△S。 ["大于","等于","小于","大于等于"]
1号主变出口CT的变比是多少()。 ["3000/5;","2500/5;","2000/5;","1500/5。"]
牙刷应多长时间更换一次() ["A、三个月","B、半年","C、用坏为止"]
膈为主要的呼吸肌,膈肌收缩时,()下降,()扩大,助吸气;()舒张时,()上升,胸腔容积减小,助呼气。