Answer:
A. Urinary system its the one system that holds waste
Explanation:
Answer: True
Explanation: Cell sends and receives signals from each other. This allows for our body to function correctly. For example your brain cells sends many signals to the rest of the body.
The solar system is considered a natural system because it was made and controlled by natural forces, meaning, it was never influenced with human creations. It is considered as one of the products of the phenomenon of the physical world. Hope this answer helps you.
Answer:
Contract; relax
Explanation:
In the patellar tendon reflex arc, the quadriceps femoris contracts when the quadriceps femoris of the the thigh is stretched through the stretching of the patellar ligament. This also causes the hamstring to relax
