apply oneself to
專心從事，埋頭于…

letter in which someone apply for a job or apply for share in a new company
某人申請獲得工作的信或購買新公司股票進行的申請

to apply a nickname
用綽號

apply one's mind to
專心于...

apply for police protection
要求警察保護

apply paint to a house
油漆房屋

apply paint lightly.
輕輕涂了一層漆

apply one thing upon another
將一件東西放在另一件之上

apply for a driving licence
申請[領取]駕駛執照

apply a theory to practice
把理論應用于實踐