hollow square beam

例句：

1. 1.The wooden beam is hollow and can be used for making furniture.
   这根木梁是空心的，可以用来制作家具。
2. 2.The hollow square beam was used to support the roof of the house.
   空心方梁被用来支撑房子的屋顶。
3. 3. The hollow square beam was a popular material in ancient times for building houses.
   空心方梁在古代是一种流行的建筑材料，用于建造房屋。