Not washing hands properly
....thanks??? lol you're supposed to ask questions on here.
Explanation: Well, A healthy balanced diet will help you build strong bones from an early age and maintain them throughout your life. You need sufficient calcium to strengthen your bones and vitamin D to help your body absorb calcium. The bones become porous and fragile, the skeleton weakens, and the risk of fractures greatly increases. ... In younger and older adults, a nutritious diet helps preserve bone mass and strength. And in those who have had a fracture, it speeds and aids recovery and reduces the risk of having another fracture.
The answer is the digestive and circulatory system.
Double? Sorry I know nothing about this and just wanted to try to help
