Single Floors, used as upper floors, consist simply of timber joists supported by the walling. Fig. 8 shows a single upper floor.是什么意思_Single Floors, used as upper floors, consist simply of timber joists supported by the walling. Fig. 8 shows a single upper floor.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句