Can someone please help me on this plz I beg u :(

Which structure in the cardiovascular system connect arteries to veins?

When is your breathing likely to speed up? a. when your white blood cells increase b. when your cells need more energy c. when your heart cells need more carbon dioxide d. when your blood cells have too much oxygen

30 points why are most volcanoes found around the ring of fire? this is a location where there are many hot spots. this is a location of numerous plate boundaries. this is a location within an active oceanic plate. this is a location of fast moving continental crust.