Question

the decomposition of plants plays an important role in the carbon cycle. three hundred million years ago, many parts of earth were covered by warm, swamp - like forests. when the trees, ferns, and other plants in these forests died, many were buried under layers of mud, water, rock, and sand. over hundreds of thousands of years, pressure and heat transformed carbon - based molecules in these dead plants into a fossil fuel called coal. which of the following statements are true? select all that apply. the formation of coal takes hundreds of thousands of years. coal forms when plants decompose on earths surface. carbon can be stored deep underground as coal. coal contains the carbon that was once part of ancient plants.

Explanation:

1. For "The formation of coal takes hundreds of thousands of years": The text says "Over hundreds of thousands of years, pressure and heat... transformed... into coal", so this is true.
2. For "Coal forms when plants decompose on Earth's surface": The text states plants were "buried under layers of mud, water, rock, and sand" before forming coal, not on the surface, so this is false (but the checkmark in the image is incorrect here; however, we analyze based on the text).
3. For "Carbon can be stored deep underground as coal": Since plants were buried and transformed into coal underground, carbon is stored there, so this is true.
4. For "Coal contains the carbon that was once part of ancient plants": The text says "pressure and heat transformed carbon - based molecules in these dead plants into... coal", so this is true.

Answer:

• The formation of coal takes hundreds of thousands of years.
• Carbon can be stored deep underground as coal.
• Coal contains the carbon that was once part of ancient plants.