keel beam

• 龙骨

keel beam的用法和样例：

例句

1. The keel of the boat was made of steel.
   这船的龙骨是钢制的。
2. The keel of her sister ship will be laid by the time she discharges at Calcutta.
   等它在加尔各答卸货的时候，它的姊妹船的龙骨就会铺好啦。