The correct answer is: [B]: "decreased" .
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<u>Note</u>:
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In a graph of "coal reserves in the United States" vs. "time" ;
→ the "time" is the "independent variable" that belongs on the "x-axis" .
→ The quantity or amount of "coal reserves in the United States" is the "dependent variable" that belongs on the "y-axis" .
If the graph "slopes downward" ; this would indicate a "decrease" in the amount/quantity of "coal reserves" over "time" .
→ As the value of "x" increases — "time" increases — and; as "x" increases, the value of "y" {the amount/quantity of "coal reserves"} decreases.
→ This would be represented by a "downward sloping" graph;
→ and, among the answer choices given, could indicate that coal production:
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→ "decreased" ;
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→ which is: Answer choice: [B]: "decreased" .
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Answer: D. Plants do not eat, so both chloroplasts and mitochondria are needed to make enough energy for plants to grow.
Explanation: Option A is invalid since plant cells do use ATP. Option B is invalid since animal cells don't make their energy with chloroplasts. Option D is the most realistic one since chloroplasts in the plant are the ones that make the food for the plants, plant doesn't have a "mouth" so they depend on chloroplast to make food.
A chemical reaction is a process in which one or more substances are changed into new substances.
An example of a chemical reaction is when metal rusts.
D) Thorns are an adaptation that some plants have evolved in order to discourage herbivores from eating the plant.
Animals have many advantages. But plants can make food anywhere there is sunlight/ultraviolet rays. So no need to hunt unless you're a Venus Flytrap. So plant cells can sustain themselves easier to a degree. As with many things in biology, it all comes down the the circumstances.