双段煤气发生炉顶部煤气温度偏高的原因是什么？
铝塑复合管燃气管独有（），杜绝气体渗漏，确保燃气输送安全。 ["中间金属塑层","中间金属铝层","中间金属铁层","中间金属铜层"]
在Word的常用工具栏中“显示/隐藏编辑标记”按钮未被按下时，（）。 ["A.WORD文档中的分节符只有在普通视图方式中才可见到","B.WORD文档中的分节符可以在大纲视图方式中见到","C.WORD文档中的分节符可以在页面视图方式中见到","D.WORD文档中的分节符可以在任何视图方式下显示"]
An acceptable method of measuring for the correct rotational force applied to the connecting rod and main bearing bolts, is to use a（） ["torque wrench","monkey wrench","pipe wrench","slugging wrench"]
A vessel is tender if cargo weight is（）. ["concentrated high and the double bottoms empty","concentrated low and the double bottoms empty","evenly distributed vertically with the double bottoms full","concentrated and with the double bottoms full"]
为了保证客室换气，每辆车设置（）个自然排风装置。
