A.低鈣鎂橡膠襯里 B.樟丹漆 C.環(huán)氧樹(shù)脂 D.過(guò)氯乙稀
A.電極反轉(zhuǎn) B.葉輪中有空氣 C.葉輪松動(dòng) D.出口閥壞
A.30PPb B.25PPb C.5PPb D.100PPb