Answer:
c mantle to core collision
In facilitated diffusion molecules only move with the aid of a protein in the membrane. Normal diffusion requires molecules to move through a special doorway
The tundra and the savanna desert
Answer:
Sinkholes can occur when<u> excessive water use lowers a water table and weakens the substrate.</u>
Explanation:
There are various causes for sinkholes, but all are related to water and how this can affect the soil. One of the causes of sinkholes is the excessive use of water. Excessive use lowers the volume of water in aquifers. As a consequence, the substrates that are above the aquifer change. They can not support large amounts of weight, leading to a sinkhole and soil with low permeability.
