渗水透明度过小或明显减小,可能是()所致。 ["已采取反滤排水措施效果较差","反滤体失效","渗流量小","渗流加剧导致渗透破坏","临背河水位差小"]
硅PN结的正向导通电压约为(). ["A.小于0.1V","B.0.2~0.3V","C.0.6~0.7V","D.大于1V"]
离心泵启动后排液中断一般是什么原因?
A11消息-注册请求应答,返回的代码为(),表示Unkonwn PCF。 ["131","00","129","130"]
观测分析渗水透明度时,()的情况都不正常。 ["透明度稳定","透明度过小","相同条件下透明度明显减小","透明度适中","水位稍有增高而透明度明显减小"]
最常见的密封装置有哪几类?