进行惰性气体保护焊焊接时，（）会使板件变形。 A.使用大电流。 B.使用分段焊接。 C.使用脉冲点焊。 D.放慢焊接速度。
Care must be taken to condition the （）in the boiler to prevent scaling, and corrosion, which can weaken the pressure vessel. water。 fuel。 steam。 air。
A vessel proceeding along the course of a narrow channel shall keep as near to the outer limitof the channel which lies on her starboard side as it is safe and practicable.Which one of the followings does the statement express?（）. A vessel shall proceed near the other vessel on her starboard side on the narrow channel since it is safe and practicable。 A vessel shall avoid proceeding near the starboard outer limit of a narrow channel as long as it is safe and practicable。 A vessel shall avoid proceeding along the channel because it is not safe and practicable。 A vessel shall proceed near the starboard outer limit of a narrow channel to the degree in which it is safe and practicable。
交直流接触器的差别可从以下哪几部分判别（）。 短路环。 铁心。 线圈匝数。 线圈线径。 触头形式。 接触器结构。
船舶在码头装卸货期间发生火灾，火势较大时，如认为可以自救，就不必向岸方消防队报警。
农信银专项汇款支持的账户类型为（）。
