The graph shows an approximation of the predicted life expectancy of a main sequence star based on its mass. Our Sun is a main sequence star with a mass of approximately 1.9 x 1030 kilograms.
Current estimates put its age at around 4 billion years. Which of the following is the most reasonable
prediction of how many more years our Sun will last

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

the wires in the toaster turning red and the toast crisping and turning brown

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.