13.Explain the difference between Selling expenses and General & Administrative expenses. During Covid, what do you think happened with these categories? 14. This is a December 31 2020 Income Statement. The company has depreciation expense on the statement. How does a company know what to depreciate and how much? 15.Under "Other revenues and gains (expenses and losses)" what is the difference between Interest Revenue and Interest Expense? Not the dollar amount, explain where those numbers came from