Question

HELPPPPP AGAIN! I WOULD APPRECIATE IT

Answer 1

Common concerns about the Internet
Negative aspects of using social media
Problematic uses of social media among teenagers
Teens' use of social media for cyber bullying

There actually was no need to change them from the original format!

Answer 2

I think its correct the way it is 
like: 
Common concerns about the Internet
Negative aspects of using social media
Problematic uses of social media among teenagers
Teens' use of social media for cyber bullying