1
it is used to do/for doing math operations
2
you can use them to listen/for listening to music
3
It's an app used to chat/for chatting with people and sending content
4
they can be used to replace/for replacing humans in dangerous or repetitive tasks
5
They are often used to communicate/for communicating with others in a formal way
6
people use it to enter/for entering to the different apps and oonline services
7
it is used to take/ for taking photos and make/making videos
