Please circle either debit or credit in each of the following $(2$ marks each$).$

a$.$ Capital purchases usually have a debit or credit balance?

b$.$ Room rental income usually has a debit or credit balance?

c$.$ Travel expense usually has a debit or credit balance?

d$.$ Salary Payable has a debit or credit balance?

e$.$ Accounts payable are usually a debit or credit balance?

f$.$ Accounts receivable are usually a debit or credit balance?