环境质量指数是一种() ["无量纲的评价标准","分级的评价体系","由若干个评价参数组成的评价标准","无权重的综合评价指数","由监测数据代表值经环境质量标准评价的综合指数"]
卧床患者更换床单法的注意事项是什么?
某日某区域空气污染指数(API)的各分指数为:SO2100,NO290,PM10160。此日该区域空气的API为() ["90","160","150","200","450"]
中度昏迷与深昏迷最有价值的鉴别点是() ["各种刺激无反应","不能唤醒","无自主运动","深浅反射均消失","大小便失禁"]
按照大气质量指数评价大气环境质量,可以分为五级,其中Ⅱ级为() ["重度污染","中度污染","轻度污染","尚清洁","清洁"]
何谓卧床患者更换床单法?它的目的是什么?