Therefore, what seems to have been the major cause of the dramatic change in the composition of earth's atmosphere of the past 4.5 billion years

Billions of years back the gasses in the climate of the earth. The environment was influenced generally to out of carbon dioxide (C02). This implied there was no ozone layer as the gasses had consumed it with extreme heat. Be that as it may, 200 million years back coal began shaping and when the coal framed it retained and caught the CO2 in it. More than a large number of years, carbon dioxide levels diminished and diminished. In the end, there was sufficiently less CO2 for plants to begin becoming out of the disintegrated soils. At the point when plants began developing they what we photosynthesized. This implied they took in the CO2 and discharged what we make due on oxygen. Presently creature life began to shape. More oxygen was created, and carbon dioxide was progressively vanishing. As the years passed by mankind was framed. People started to take in more things about the earth. They likewise started to learn new aptitudes.

1) d 2) d 3) c 4) d 5) a 6) c 7) a 8) b 9) a 10) a 11) d 12) c 13) c 14) d 15) a 16) a 17) d 18) c 19) c 20) c