one-direction truss

例句：

1. 1.The engineer designed the bridge to be a one-direction truss.
   工程师设计这座桥为单向桁架。
2. 2.The construction of this bridge required a one-direction truss.
   建造这座桥需要使用单向桁架。
3. 3. The one-direction truss was used to support the weight of the building.
   单向桁架被用来支撑建筑物的重量。