For each of the following accounts, indicate whether it normally has a debit or a credit balance. Use dr. or cr:
1. Sales revenue
2. Trade and other payables
3. Trade and other receivables
4. Interest expense
5. Inventory
6. Interest income
7. Retained earnings
8. Depreciation expense
9. Dividends payable
10. Issued capital
11. Bad debt provision
12. Accumulated depreciation.