Mobile phone is a very useful device.
Nowadays some people can hardly imagine themselves without mobile phones.
If they leave it at home they feel quite helpless.
The main advantage of a phone is that you can keep in touch with people in any place and in any time.
It is very useful if you need help.
Modern mobile phones are multi-function.
You can play games, listen to music, find information in the Internet, take photos and so on.
We take it use it everywhere.