팔팔카 Poll of the Day
https://www.evernote.com/shard/s703/sh/38d3a16b-8eb4-421d-5d1c-476179c95869/9e6a842235103054f56d2fc5a9de2db7
These drawings explain the main points of the objects supporting customers, for instance beams and columns, which might be designed via the structural engineer.