Answer: She has a good and strong immune system which helps Andrea to remain fit and strong.
Explanation:
Andrea works in an office where frequent breakouts and viruses occur very frequently. Despite of this unhealthy environment Andrea remains fit and does not gets affected by the environment in which she is living in.
The immune system of Andrea is developed and it kills the bacteria and virus entering the body.
The white blood cells and other phagocytotic cells kill the harmful organism entering the body and keeps the body healthy.
Answer: Sea stars move using a water vascular system. Water comes into the system via the madreporite. It is then circulated from the stone canal to the ring canal and into the radial canals.
Explanation: The radial canals carry water to the ampullae and provide suction to the tube feet.
