The steel piece goes through the lap and welding with the lap, to guarantee its stability.
2
船尾那里有一个方孔,大小只够我父亲膝盖顶着下巴挤进去。
There was a square hole just large enough for my father to fit into if he pulled his knees up to his chest.
3
双线圈装用连续的双圈铁丝绕穿过打在书本订口的方孔而成的一种活页装。
Wire-o binding a method of loose-leaf binding in which a continuous double loop of wire runs through punched slots along the binding side of a booklet.