1. onions: Onions are vegetables, while lemons, limes, and oranges are fruits.
2. snails: Snails are animals, while mangoes, limes, and grapes are fruits.
3. peas: Peas are vegetables (or legumes), while carrots and pineapples are fruits.
4. sandwiches: Sandwiches are food made from bread and other ingredients, while bananas and pears are fruits.
Onions are vegetables.