Answer:
make me brainest
Explanation:
the heart , blood, blood vessels form the circulatory system 
 
        
             
        
        
        
Over half of the people in the United States rely on groundwater for drinking water. This is true.
        
                    
             
        
        
        
Answer:
dear user the answer is option A.oxygen level and water temperature and C.salinity and water temperature.
hope this helps 
if it's useful to u plz thank and try to mark as brainliest 
 
        
             
        
        
        
The heart, lungs, blood vessels, and blood
        
                    
             
        
        
        
Answer:
The options are not given but they are gotten from another websites.
A. Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells.
B. Capillaries surrounding the brain have pores and are surrounded by membranes of astrocyte cells.
C. Capillaries surrounding the brain have no pores and are not surrounded by membranes of astrocyte cells.
D. Capillaries surrounding the brain have pores and are not surrounded by membranes of astrocyte cells.
The correct answer is option A.
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells.
Explanation:
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells because
Capillaries are tiny blood vessels in the circulatory system that connect aterioles to venules. They are the most abundant or they are much blood vessels. They can penetrate the tissues of the body which allow passage of food nutrients, oxygen in the body thereby allowing exchange of nutrients and oxygen between the body tissues and the blood.
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells while capillaries in the periphery Capillaries surrounding the brain have pores and are not surrounded by membranes of astrocyte cells.