Classify each item as income or expense: Commission income, Consumable stores, Postage.

Here's whether each item is an income or an expense:

• 7.8 Commission income: $\boxed{\text{Income}}$
• 7.9 Consumable stores: $\boxed{\text{Expense}}$
• 7.10 Postage: $\boxed{\text{Expense}}$