plain reducing cross

例句：

1. 1. Theengineer designed the bridge to have a plainreducing cross section.
   工程师设计这座桥时，采用了平直剪力杆截面。
2. 2. Theconstruction of the new highway required the installationof several plain reducing crosses.
   新高速公路的建设需要安装几根平直剪力杆。
3. 3. The plain reducing cross is an importantcomponent of the bridge's design.
   平直剪力杆是桥梁设计中的一个重要组成部分。