Air polution can cause things such as asthma, lung cancer, and many other things. air polution could also cause headaches, dizziness, nausea, and more.
It gives a better foundation for the top part of your vertebrae (that are smaller), as it is bigger, it can support the rest of your vertebrae better.
friction is a force that opposes motion and significantly slows the cars as they move on the track. While it is easy to believe that friction is bad for the ride, it is one of the forces engineers consider in ensuring passengers have a safe ride.
Cellular differentiation is the process in which a cell changes from one cell type to another. Usually, the cell changes to a more specialized type. Differentiation occurs numerous times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. So I believe the answer you are looking for would be the third one :)
Hope this helps! Please let me know if I'm wrong :)
