Read the sentences and decide which one of the given words fits each gap in the expressions:
1. You need to log ______ before you can start using it.
2. It takes ages for my computer to boot ______ in the morning. I turn it on and go off for a coffee.
3. You need to switch it ______ using this button before you can use it.
4. It's not enough to just delete the information. It is still there and can be recovered. You need to wipe it ______ with a special program.