8 c m <span>changes to the </span>magnitude and the sign of the focal length when the lens is flipped over<span>
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The answer to your question is It gives something new to the design.
They could be played by "Player Pianos"
Answer:
so basically if you need any help with homework or have any questions u just post a question,like u did rn. u also have to answer other peoples questions to get more point:)