- 问题详情:Before1840architectsandbuildersmadebuildingsfromstone,brick,orwood.Theoutsidewallshelduptheweightofthebuilding.Abuildingthathadmorethanafewstoriesbecameveryheavy.Atallbuilding,suchasacastle,hadverythickwalls.Astimewentby,architecturebegantoch...
- 6953