对重的作用是() ["平衡轿厢重量","减少能量消耗","构成合适的曳引力","提高电梯速度"]
一般电梯的端站保护开关由（）组成 ["极限开关","限位开关","强迫换速开关","平层装置"]
电梯导轨的安装要求() ["与支架之间采用焊接固定","工作面每五米垂直度偏差不大于0.6mm","轿厢侧导轨顶面间距偏差0-+2mm","每根导轨至少要有两个固定支架","相邻固定支架之间的间距不得大于2.5m"]
低热()中等度热() ["37.5℃～38℃","39.1℃～41℃","38.1℃～39℃",">41℃","39.1℃～40℃"]
高热()超高热() ["37.5℃～38℃","39.1℃～41℃","38.1℃～39℃",">410C","39.1℃～40℃"]
稽留热可见于()弛张热可见于()
