<span>To get the most use from your exercise, stay in your target heart rate range for at least 20 minutes during an exercise session.</span>
D. Pathogen. :) I hope it right :)
Fragile
Osteoporosis is the reduction of the bone density of the bones of the body. This makes bones more susceptible to fracture, and there are a number of factors enhancing the chances of the development of osteoporosis in an individual. These factors include lack of calcium and vitamin D in the diet, genetics, lack of exercise, cigarette smoking, excessive drinking and many more.
The skeletal system. Including bones and cartiladge.
