portal shaft

例句：

1. 1. The portal shaft is themain support for the building's entrance.
   门廊轴是建筑入口的主要支撑。
2. 2. Theportal shaft was made of wood and hada decorative design on it.
   门廊轴由木头制成，上面装饰有图案。
3. 3. Theportal shaft was removed to make way fora new addition to the building.
   为了给建筑增加新的部分，移除了门廊轴。