Here's why:

* C=O (Carbonyl bond): The carbon-oxygen double bond is polar because oxygen is much more electronegative than carbon. This means the oxygen atom attracts the shared electrons more strongly, leading to a partial negative charge on the oxygen and a partial positive charge on the carbon.

* C-O (Hydroxyl bond): The carbon-oxygen single bond in the hydroxyl group (-OH) is also polar due to the same electronegativity difference. This results in a partial negative charge on the oxygen and a partial positive charge on the carbon.

Therefore, the carboxyl group contains two polar covalent bonds.