含鞣质类的药物不宜用哪类工具进行炮制加工（） ["木器","砂锅","铁器","瓷器"]
下列激励方式属于企业成熟阶段激励模式的是（）。 ["短期激励为主","股权激励","精神激励","技术创新激励"]
一个站点至少需要（）DNS服务器。 ["A.1个","B.2个","C.3个","D.不需要"]
What type of stern tube bearing has the least friction（）. ["Oil-lubricated bearings","Lignum vitae","Hard rubber","Bronze bushing"]
设备是怎样分类的，它一般有几种？
叙述可编程序控制器编程的基本原则。
