求翻译：　　2. 放线：根据设计施工图，在已做好的地面或地枕带上，放出隔墙位置线、门窗洞口边框线，并放好顶龙骨位置边线。是什么意思？

　　2. payoff: according to the design and construction, on the ground or pillow that is ready and released the position line of partition, door and window openings border line, and put away the top of keel line.