The firmness of muscles is called the muscle tone. http://www.shapesense.com/fitness-exercise/articles/muscle-tone.aspx
Answer:
Exercise can positively affect you environmental health by allowing your body to stretch and gain muscle.
Explanation:
I believe the skeletal system Provides the body with a strong mobile....and to supply the body with minerals
The immune system usually protects from bacteria, injury and diseases.
Because in the first weeks of pregnancy it is the developmental stage for major organs so if they embryo is exposed to toxins it could damage the embyro and it could cause developmental damage and stunt the growth of the baby and perhaps give the baby permanent damage throughout the bays life.