Something that could cause someone to use social media may be the excitement of being in contact with different people around the world, or seeing funny memes, or videos, but cyber bullying can cause many to become depressed, people can be ruthless and bully one for their appearance, race, sexual orientation, religion, financial state, clothes, disabilities, etc.
Pathogens usually enter our bodies through the eyes, mouth, nose, or urogenital openings, or through wounds or bites that breach the skin barrier. Organisms can spread, or be transmitted, by several routes.
So i would say no, that is false?
Look at the way that they act. If they are into doing rebellious things, that could be bad. If they hang out with kids that you know aren't good kids, that could also be bad. If they ask you if you want some drugs or alcohol, that is DEFINITELY bad.
Polio destroys motor neurons specifically. The question came with no "Which of these options"