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 transfer of heat in the atmosphere by winds that circulate between the equator and the poles is an example of  
 (A) radiation. (B) insulation. (C) convection. (D) conduction.

A: C
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Q: A movie studio will use two methods of communication, television and the Internet, to advertise a new movie. Which of the following must both methods of communication use in order to show the advertisements to viewers around the world?  
 (A) systems to locate viewers (B) networks to transmit signals (C) printing to create the images (D) software to search for images

A: B
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Q: In the 1600s a scientist named Anton van Leeuwenhoek worked toward improving microscopes and created his own lenses. With his microscopes, Leeuwenhoek discovered bacteria and muscle fibers. Which type of job benefited most from these discoveries?  
 (A) glass making (B) astronomy (C) medicine (D) teaching

A:
C
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