What types of food are preserved by oil and vinegar? 

Oil and vinegar are commonly used to preserve meats and fish. The acidic vinegar helps prevent the growth of bacteria, while the oil creates an airtight seal that slows down the oxidation process and prevents the food from drying out. This allows the preserved food to be stored for longer periods of time without spoiling or becoming inedible. Additionally, the combination of vinegar and oil can impart unique flavors to the preserved food, making it a popular technique for making pickled and marinated meats and fish.