In 1928, Freysinet used the cantilever concept to construct the springings of the arch rib in the Plougastel Bridge.是什么意思_In 1928, Freysinet used the cantilever concept to construct the springings of the arch rib in the Plougastel Bridge.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句