Answer:
excretory system and circulatory system
Explanation:
Blood is part of circulatory system and as it move through various organs it exchanges the gases i.e give oxygen to the cell and take carbon dioxide from them. After taking CO2, the blood becomes impure and hence it passes through the kidney before going to the heart. Kidney is part of excretory system which removes carbon dioxide from blood and thus purifies it.
<span>Atherosclerosis is a common cause, because there is a lack of blood flow in the person's body, and this can cause a male to be impotent.
Diabetes is also a common cause because once again it causes less blood flow.
In a younger man, a cause could be anxiety. This is because nervousness and being anxious can lessen blood flow.
If you have choices, I suggest choosing one that has to do with less blood flow happening, which that is the main cause.
I hope that this could possibly help you with your studies, and have an amazing day. If you have any more questions, send me a pm. </span>
Answer:
special type of relationship between species.
Explanation: