Which rocks come from cemented shell fragments?

coquina

Explanation:

coquina is a sedimentary rock that is composed wholly or almost entirely of the transported abraded and mechanically fragments of the shell of moluscs

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.