Which parts of the circulatory system make up the network of vessels by which the heart pumps blood through the body?
a.
lungs, heart, and brain
b.
capillary, vein, and artery
c.
type a, type b, type ab, and type o
d.
platelets, plasma and oxygen

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds