I believe the correct answer would be A. The extraction of oil shale is detrimental to the environment mainly because the process of extraction requires large amounts of land. Lands are being excavated in order to locate areas which contains the oil. This is not good since it affects ecosystems and destroy habitats.
360 degrees. I'm pretty sure
Friction can be reduced by making the surface smoother, lubricating the surface, or reducing the contact between the forces.
Hope this helps!
