<span>palisade and spongy layers of the mesophyll are </span>the two layers of the plant containing chloroplasts
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.
The condensation of water vapor formed the early oceans. It is an important part of the water cycle. It is easy to eliminate the other answers in this question. It can't be meteorites, living organisms, or nitrogen.
External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.