以下是利用大小差别来分离纯化蛋白质的技术手段有（） ["凝胶过滤层析","双向电泳","差速离心","亲和层析"]
简述浆纱工程。
Which of the following procedures decreases the total dissolved solids concentration in the water of an auxiliary boiler?（） ["Hydrazine treatment of condensate","Frequent compounding","Chemical cleaning","Bottom blowing"]
在实际操作中，质物一般都有单价，这个单价是由（）给出的。 ["出质人","质权人","监管人","融资人"]
Failure of the burner flame in an auxiliary boiler would probably be a result of（） ["water in the fuel oil","broken high tension leads","incorrect electrode setting","full fuel pressure at the nozzle"]
接于主变20千伏母线桥的接地变调度运行及故障处理有何要求？
