Find explanations to the phrase

to phone back	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you
to hang up	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you
to hang up on sb	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you
to pick up the phone	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you
to put the phone down	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you
voice mail	??? to phone someone who has called you earlier to lift up your telephone receiver to put the receiver back onto the phone to finish a phone conversation by putting the receiver down to put the receiver down before they have finished speaking an electronic system on your phone that lets you leave messages for people who phone you when you are not available and lets them leave messages for you