The reference point = a object used for comparison to determine if something is in motion.
An object is in motion if it changes position relative to a reference point.
You assume that the reference point is stationary, or not moving.
Answer:
below
Explanation:
it prevents recessive traits which often causes diseases or defects
I think the correct answer from the choices listed above is option b. A permeable rock weathers easily because it <span>contains many small, connected airspaces. Its porosity is very high that it can easily be destroyed by simple means. Hope this answers the question.</span>