A compound is organic if it contains carbon covalently bonded to other atoms. Most often, the other atoms include hydrogen, oxygen, and/or nitrogen. A few carbon compounds, such as simple oxides (e.g. CO2) and cyanides (e.g. KCN) are excluded arbitrarily.
 
        
             
        
        
        
I believe it is a microscope
        
             
        
        
        
Surface ocean currents form large circularpatterns called gyres. Gyres flowclockwise in Northern Hemisphereoceans and counterclockwise in Southern Hemisphere oceans.
        
             
        
        
        
Answer:
d. blood moves from the heart into arteries and into smaller vessels and then back into larger vessels as it makes its way back to the heart.
Explanation:
A closed circulatory system is a system in which blood is separated from the interstitial fluid as it circulates in the blood vessels. In a closed circulatory system blood circulates in one direction that is from the heart and then then returns to the heart again after circulating around one of two routes of circulation. A closed circulatory system can be observed in vertebrates, annelids, mollusks.  
 
        
             
        
        
        
Answer:
I guess the answer to the question is ecology.