短语词组短語bowstring g truss 弓弦桁架bowstring roof truss 弓弦屋架;拱形屋架;弓弦式屋架double bowstring truss 雙弓弦桁架;魚形桁架laminated bowstring truss 曡層弓弦桁架truncated bowstring truss 平耑弓形桁架;平截耑弓形桁架ribbon grenext tod bowstring truss 弓弦桁架 返回 bowstring truss