Various steps that have been taken are:
To protect ozone, we have to curb CFC's. They react with ozone to deplete it.
The ozone layer can be protected. It can be done so by avoiding CFC's.
To limit the destruction of ozone, many steps have been taken. Banning of CFC's is the main.
Ozone layer needs to be replenished. It is because of its destruction.
Ozone layer has been destroyed by CFC's. They react with ozone to deplete it.
The ozone layer is being protected. It is done by spreading awareness.
Aerosols have affected the ozone layer. They have done this as they contain CFC's.
See "What can we do to protect the ozone layer?" in the "Related questions" section below
Man has depleted the ozone layer. He has done this by continues usage of CFC's.
In order to repair the ozone layer, we must decrease the use of ozone depleting substances. These are the ones containing CFC's which deplete the ozone layer.
Montreal Protocol has been established. It has placed a ban on CFC's.
In order to stop the ozone depletion, the use of CFC's has been banned. These CFC deplete the ozone by decomposing it.