Baroreceptors. These are found in the carotids and aortic arch. They respond to pressure exerted on the vessels.
I think the correct answer from the choices listed above is option B. Keratin is the protein in mammals which shows only a primary and secondary structure. Keratin is a fibrous protein forming the structural constituent of hair, feathers, hoofs, claws and many others.
Because water can dent things. You seen the movie 2012? Think of the aftermath. Think about japan. The canyons had to do with something about water
