sentence: Spelunkers choose different knots for different purposes.
sentences_before: Spelunkers tie their ropes with different kinds of knots, like the 'farmer's hitch knot' and the 'alpine butterfly knot'.
sentences_after: Some knots work well to hold people as they climb. Other knots are best for tying ropes together.
concept_name: spelunker
headings: Caving Spelunkers and their equipment
categories: Hobbies Caves