They construct dams and create an ecosystem for other species . Because of their dam building nests become available for birds, fish population increases and waterfowl population goes up
The immune system helps neutralize disease and infection. The digestive system processes nutrients from food. The skeletal system includes your bones and supports and protects your body. The correct answer is the nervous system.
Answer:
The respitory system and the nervous system.
Explanation:
I'm pretty sure
