Spread of disease is the answer.
Disease can cause an epidemic which can lead to mass population decline.
Adult frogs are on land and they have feet and a body
Tadpoles are in water and they are somewhat like a fish!
Answer:
Muscles connect to your skeleton and they contract and move the skeleton along. Your skeletal system is made up of cartilage and calcified bone that work together. They help the process of movement happen in a smoother manner. The calcified bones of your skeleton also work with the circulatory system.
