Final answer:
Olive oil is a good source of monounsaturated fatty acids, predominantly oleic acid, and is liquid at room temperature but solidifies when cooled.
Step-by-step explanation:
Olive oil is an especially good source of monounsaturated fatty acids. These are fats that contain one double bond in their molecular structure and are known for being liquid at room temperature but starting to solidify at cooler temperatures like those in a refrigerator. The most common monounsaturated fat found in olive oil is oleic acid. Monounsaturated fats are considered healthy dietary fats and are also found in other foods like peanut oil and avocados. While olive oil contains predominantly monounsaturated fats, it also has some polyunsaturated and even saturated fatty acids.