Adolescence /ˌæd

apply /əˈplaɪ/ verb REQUEST
1. [ I ] to request something, usually officially, especially by writing or sending in a form
By the time I saw the job advertised it was already too late to apply.
Please apply in writing to the address below.
We've applied to a charitable organization for a grant for the project.
[ + to infinitive ] Tim's applied to join the police.
apply /əˈplaɪ/ verb WORK HARD
5. apply yourself
[ R ] If you apply yourself to something, you work hard at it, directing your abilities and efforts in a determined way so that you succeed
You can solve any problem if you apply yourself.
apply /əˈplaɪ/ verb RELATE TO
2. [ I ] (especially of rules or laws) to have a connection or be important
That bit of the form is for UK citizens - it doesn't apply to you.
Those were old regulations - they don't apply any more.