Two reasons: Aspirin has a direct potentially erosive effect on the stomach lining causing the lining to become inflamed , especially on an empty stomach and thus can contribute to creation or perpetuation of a breach in the stomach lining (an ulcer).
Photosynthesis is a process used by plants in which energy from sunlight is used to convert carbon dioxide and water into molecules needed for growth. These molecules include sugars, enzymes and chlorophyll.
Plants absorb energy from sunlight to produce sugar that is used to energize themselves. They convert solar energy from the sun into chemical energy stored in the form of glucose (i.e. sugar). Along with sunlight and water, carbon dioxide is transformed into food for plants.