tenasco

例句：

1. 1. The old car's engine has developed a tenasco on the piston ring.
   这辆旧车引擎的活塞环上长了铁锈。
2. 2. He noticed that the paint on the fence had turned into a tenasco.
   他注意到围栏上的油漆已经变成了铁锈。
3. 3. The rusty nails were difficult to remove from the wall.
   生锈的钉子很难从墙上拔下来。