secondary truss

例句：

1. 1.The engineer designed a secondary truss to support the roof.
   工程师设计了一根次要桁架来支撑屋顶。
2. 2. The construction of the bridge involved the use of secondary truss.
   桥梁的建设使用了次要桁架。
3. 3.The secondary truss is essential for the stability of the structure.
   次要桁架对于结构的稳定性至关重要。