backshank

例句：

1. 1.The backshank of the chair isworn smooth from use.
   椅子的后跟因使用而磨损光滑。
2. 2. Thebackshank of thecar is made of steel.
   汽车的后跟是由钢制成的。
3. 3. Thebackshank of the bike is strongand durable.
   自行车的后跟很坚固耐用。