Answer:
because the want to reach their destination
Answer;
-Synovial cavity
Explanation;
-The synovial cavity/joint is filled with synovial fluid. A synovial joint contains a synovial cavity and dense, irregular connective tissue that forms the articular capsule normally associated with accessory ligaments.
-A synovial joint occurs at articulating bones to allow movement. It is distinguished by a surrounding synovial capsule.The bones of a synovial joint are surrounded by a synovial capsule, which secretes synovial fluid to lubricate and nourish the joint while acting as a shock absorber.
Diaphragm...is the muscle that helps in respiration.....there are also some other but....you said flat so diaphragm !
Answer:
https://www.biology-pages.info/T/Tropisms.html
Explanation:
This link holds all the information you need :D
