Answer:
D.
Explanation:
She's trying to find the affect different shapes have on the distance the plane flies, not the affect different types of paper have on distance. If she were to use different paper for each plane she'd be testing two variables instead of one.
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Answer:Genetic engineering, also called recombination DNA technology, involves the group of techniques used to cut up and join together genetic material, especially DNA from different biological species, and to introduce the resulting hybrid DNA into an organism in order to form new combinations of heritable genetic material.
Explanation: