Explanation:

- Advancing Loans: This is a primary function of commercial banks. They lend money to individuals and businesses, earning interest from the loaned amount.

- Accepting Deposits: This core function involves banks accepting money from the public, offering them security and sometimes interest in return.

- Act as Trustee: This is where banks act on behalf of individuals or entities to manage assets or a property. It's an agency function because the bank operates as an agent for their clients.

- Locker Facility: This is a supplementary service offered by banks for the safe-keeping of valuables and documents.