- Taking in carbon dioxide is a stage in the photosynthesis process
- If something is a stage in a process then that something helps that process
- Hence, taking in carbon dioxide helps the photosynthesis process

- Taking in carbon dioxide helps the photosynthesis process
- Carbon dioxide can be found in the air
- Hence, taking in carbon dioxide from the air helps the photosynthesis process

- Taking in carbon dioxide from the air helps the photosynthesis process
- Photosynthesis is a source of / makes food / energy for the plant by converting carbon dioxide, water, and sunlight into carbohydrates
- Hence, taking in carbon dioxide helps a plant make food

Hence, taking in carbon dioxide helps a plant make food
Q: What do plants take from the air that helps them make food?
Context:
- Carbon dioxide can be found in the air 
- Photosynthesis is a source of / makes food / energy for the plant by converting carbon dioxide, water, and sunlight into carbohydrates 
- Taking in carbon dioxide is a stage in the photosynthesis process 
- If something is a stage in a process then that something helps that process