Which two of the following sentences contain ideas that should be included in a summary of the article? 1. The sea slugs known as sacoglossans are some of the most remarkable biological burglars on the planet.

2. Chlorophyll is used in photosynthesis, a process by which plants capture the sun's energy and combine it with carbon dioxide and water to make food.

3. Gould's theory is that the slugs are just doing something lots of critters do: saving some of the food they collect for times of hardship.

4. The chloroplasts E. chlorotica captures from the algae it eats primarily make lipids, which provide both energy and building materials for cells.