a length of rope的用法和样例：
- The anchor was attached to a length of rope.
- Twist a length of rope from strands of hemp.
- To secure(a mountain climber, for example) at the end of a length of rope.
- He fished a length of string out of his pocket.
- The poachers attach the spear to a length of rope, throw the spear into a hippo, and then pull out and repeat until the animal is dead.