$1.$ Common$-$size analysis is a simple way to make financial statements of different firms comparable. What are possible shortcomings of comparing two different firms using common$-$size analysis? Please provide three shortcomings with explanations for each.

$2.$ The intuition behind the benefits of financial leverage is that a firm can borrow funds that bear a certain interest rate but invest those funds in assets that generate returns in excess of that rate. Why would firms with high ROA$$s not keeping leveraging up their firm by borrowing and investing the funds in profitable assets.