longitudinal plane of symmetry

例句：

1. 1.The car is longitudinally welded to the frame.
   这辆车是纵向焊接到车架的。
2. 2. The train travels longitudinally across the country.
   火车沿着国家纵线旅行。
3. 3. The beam is longitudinally reinforced with steel plates.
   梁是用钢板纵向加固的。