Answer:
4
Explanation:
The circulatory system includes the blood that has picked up the carbon dioxide from all of the respiring tissues and who also delivered oxygen to them to continue respiring.
The blood will then reach the lung where the carbon dioxide that the tissues released is exchanged for oxygen in the alveoli.
* Blood cells isn't an organ system which makes 1 incorrect.
* Digestive system will in no way bring the blood to the lungs or away from it. This is the circulatory system's job. So 2 is incorrect.
*Lastly, lungs are organs and the question asks for organ systems. So 3 is incorrect.
c i think but im not entirely sure to be honest with you
Answer:
Two reasons why the use of synthetic fertilizers is not the answer to decreasing soil quality are:
- They increase the nitrate levels in the soil which is a rich supplement for nitrogen needed by plants for their growth.
- They are easily available and user-friendly but should be used in regulated amounts as an excess of nutrients like nitrogen and phosphorus present in synthetic fertilizers enter the aquatic ecosystem.
<u>Explanation:
</u>
Synthetic fertilizers are made up of three main nutrients, viz, nitrogen, potassium and phosphorus. All of these are required for the proper growth of plants. Though, these fertilizers give higher yields, yet their excessive use is bad for aquatic ecosystems.
When these fertilizers are used in excessive amounts, they reduce the dissolved oxygen in the water as there’s an increase of bacteria and algae in the water. That is why such fertilizers should be used in regulated amounts.
