Answer:
because of factories and cars and smoking
Explanation:
Explanation:
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells.
cells are bigger than atoms. We can see cells with a microscope. Just as atoms have smaller parts called protons, neutrons, and electrons, cells have smaller parts, too. When you look at cells with a powerful microscope, you can clearly see hundreds of them.
Photosynthesis and chemosynthesis Let me know if you want me to explain more in depth.
