What is meant by the following statement? "inertia is directly proportional to mass."

It means that the greater the inertia, the greater the mass, and the less the mass, the less inertia, is what is known as Newton's first Law.

Explanation:

Newton's first law states that every body continues in its state of rest or in a uniform and straight line movement, as long as there is no external force that modifies it. The inertia is directly proportional to the mass, which means that the greater the mass, the greater the inertia, the smaller the mass, the less inertia.

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 circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.