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.
coal forms when plants decompose on earth’s surface.
carbon can be stored deep underground as coal.
coal contains the carbon that was once part of ancient plants.
the formation of coal takes hundreds of thousands of years.

Explanation:

• The text states that plants were buried under layers (not on the surface), so "Coal forms when plants decompose on Earth’s surface" is false.
• It mentions coal is formed from dead plants' carbon - based molecules, so "Carbon can be stored deep underground as coal", "Coal contains the carbon that was once part of ancient plants" are true.
• It says "Over hundreds of thousands of years" for coal formation, so "The formation of coal takes hundreds of thousands of years" is true.

Answer:

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