De qué está hecho escalera
Rungs between two uprights.
- Ladder side rails — tiene como parte. Two lengthwise uprights.
- Ladder rungs — tiene como parte. Rungs for the feet.
- Plano inclinado — utiliza. Climbing to a height.
- Fricción — utiliza. The feet hold on the floor by friction.
- Madera — está hecho de. Ladders were made of wood.