The correct answer is A.
The official guidelines from doctors state that infants should start consuming solid food after the age of six months. In order for the infants to be safe and healthy, they need to be able to sit up, support their back and chew safely before being given solid food.
prevents backflow into the left atrium
The answer is protoplasm. it contains all the other answers anyways.
It is like a barrier, or wall. It helps infection and bacteria stay out. It can also help you indicate whether you are getting infection in the inside of your body. if you're skin is inflamed, that is a sign of disease or infection.
I hope this helped you!
Brainliest answer is always appreciated!<span />
