The cell phone has changed the world, or peoples lives, because you can talk or text people from mostly everywhere without having to find an installed telephone. It has saved lives because when people are in trouble they can call or text 911.
The cell phone has also changed the world by allowing telephone service to be provided to less developed regions without the need to run wires to each telephone user. Building cell phone towers is less costly than creating landlines on a per user basis.
yes
You cannot change a phone's frequency.
It really depends on the cell phone company you have some don't let you change and some do. I would advise you to contact your local cell phone company.
Do edit, then retype the number.
No. It might damage the phone, though.
screen change
Mobile Phones
Cell phone network extenders can be a wonderful way to improve your cell phone service. They are easy to install and are an affordable option if you do not wish to change your service provider.
iphone4
No, you typically need cell service or a Wi-Fi connection to change your voicemail greeting on a cell phone.
no
Yes.