Explanation:

- Banks need to maintain a portion of deposits as reserves to ensure sufficient cash is available for withdrawals. This is necessary for liquidity purposes.

- Routine expenses of banks, like paying staff salaries and utility bills, are met through revenue generated from various banking services, not deposits.

- Extend loans: The primary function of a bank is to use deposits to provide loans, earning interest in return. This is a major way banks generate profits.

- Renovation and maintenance costs are usually covered by operating profits or allocated budgets, not directly from deposits.