You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Q: The changing appearances of the nighttime sky over the surface of Earth and eclipses of the Moon have provided evidence that  
 (A) Earth is a sphere. (B) Earth supports life. (C) Earth has a layered atmosphere. (D) Earth is covered mostly with water.

A: A
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Q: A population of ground squirrels has established a community in the grasslands of the Great Plains. Temperatures often reach -15°C for most of the winter. What is the most likely behavior the ground squirrels use to survive these winter temperatures?  
 (A) burrowing below the frost point of the soil surface (B) burrowing in tree trunks above the soil surface (C) consuming roots found under the soil surface (D) consuming organisms found in the soil surface

A: A
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Q: Which of the following is an example of genetic engineering?  
 (A) Growing a whole plant from a single cell. (B) Finding the sequences of bases in plant DNA. (C) Inserting a gene into plants that makes them resistant to insects. (D) Attaching the root of one type of plant to the stem of another type of plant.

A:
C
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