简述推焦计划制订的原则是什么？
酸性土壤中生长的植物容易出现哪些元素毒害现象？（） ["铁","锰","镁","钙"]
A shipmate suffers a heart attack and stops breathing. You must（）. ["administer oxygen","immediately check his pulse and start CPR","make the victim comfortable in a bunk","immediately give a stimulant，by force if necesssary"]
Maximum horsepower of a diesel engine is attained （）. ["when the engine RPM is pulled down by overload","at rated engine RPM","at 95 % of rated engine RPM","at 95 % of a properly adjusted governor RPM with the engine under full load"]
烧碱循环水泵跳闸，透平岗位该如何处理？
简述销售渠道的功能？
