If the cells stop dividing and do not spread, the tumor is benign
Answer:
circulatory and respiratory
Explanation:
The body system of Birds possesses a higher arrangement of organs to perform a particular function. The organs form a system which includes the organs and associated structures.
When the biologist observed the shortage of the dissolved oxygen and increase in the level of dissolved carbon dioxide, this could be the result of the failure of the circulatory system which supplies these gases on the body and the associated respiratory system which helps in the exchange of these gases with the atmosphere.
Thus, circulatory and respiratory is the correct answer.
D:Medical History because you need to know pets background to properly treat it
The answer is D.
If not sorry
1. the first choice , hope that helped