Answer:
H. It represents the actual size but it is big enough for the eye to see making it extrememly accurate
Explanation:
Oxygen entered the Earth's atmosphere after the appearance of the Great Oxidation Event (Great Oxygenation Event). The Great Oxidation is the first mass extinction on Earth.
The Great Oxidation lasted 2.4 to 2.0 billion years ago.
Oxygen appeared on Earth thanks to cyanobacteria using photosynthesis.
Photosynthesis makes the glucose that is used in cellular respiration to make Atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while the water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.
The presence of limestone<span> and other calcium carbonate rock in </span>lakes<span> and streams helps to maintain a constant pH </span>because<span> the minerals react with the excess </span>acid<span>. However, </span>acid rain<span> eventually can overcome the buffering capacity of the surface water.
</span>
