main supports的用法和样例：
例句
- The cables, which will be the bridge's main support, are strung from tower to tower. They are made up of wire that's high tensile steel.
作为大桥的主要支撑，绳索被绷在塔之间。它们是由高抗拉强度的钢丝组成的。 - A horizontal beam, as of steel or wood, used as a main support for a building or bridge.
大梁一水平的铁制或木制的桁条，用来作为建筑物或桥梁的主要支撑物
