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: A student tosses a ball into the air. Which force causes the ball to fall back to the ground?  
 (A) gravity (B) magnetism (C) mechanical (D) friction

A: A
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Q: When sodium hydroxide reacts with a copper nitrate solution, the reaction vessel needs to be kept on ice to slow down the reaction. What best describes this reaction?  
 (A) an exothermic reaction that absorbs energy (B) an exothermic reaction that releases energy (C) an endothermic reaction that absorbs energy (D) an endothermic reaction that releases energy

A: B
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Q: When the Northern Hemisphere is tilted toward the Sun, what season is occurring in Australia?  
 (A) fall (B) winter (C) spring (D) summer

A:
B
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