In order for combustion to occur inside a piping system such as a vapor collection header in a marine emmission control system，there must be（）. ["fuel","oxygen","ignition","All of the above"]
各级人民代表大会代表的选举，一律采用（）的方法。 ["举手表决","鼓掌通过","记名投票","无记名投票"]
用外交辞令互相介绍、问候寒暄、谈天说地开场，属于（） ["事实性开场白","社交性开场白","激励性开场白","以上都不是"]
什么是狭义制造与广义制造？
讲演、讲课属于哪种传播（） ["二人传播","公众传播","小群体传播","以上都不是"]
什么是机械产品的生产过程？包含有什么？
