Across
- 1. The ingredients
- 3. To change from one form to another.
- 4. It is necessary for humans, animals and plants to live.
Down
- 2. A colorless, odorless gas that is composed of carbon and oxygen.
- 3. The green substance in plants that is essential to photosynthesis.
- 5. A simple sugar that is found widely in nature and is an important energy source for plants and animals.