The main research of this paper is the optimal design of the unbonded prestressed concrete ribbed flat slabs in the ribbed flat slabs system.是什么意思_The main research of this paper is the optimal design of the unbonded prestressed concrete ribbed flat slabs in the ribbed flat slabs system.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句