sentence2_structure: Bones, cartilage, and ligaments<>make up<>the skeletal system
sentence1: Torn or damaged ligaments and tendons -- the fibrous tissues that connect bone, cartilage and muscle -- make up the bulk of sports-related injuries.
sentence2: Bones, cartilage, and ligaments make up the skeletal system.
question: Bones, cartilage, and what other thing make up the skeletal system?