For Questions 21 to 22, indicate whether the statement is True or False. Give an explanation. 21. When a gas filled in a cylinder fitted with a movable piston is allowed to expand, the
work done by the gas is positive.
22. When a body is lifted, the work done by the gravitational force is positive.

i believe so yes mindblown

they were destroyed coming out of the civil war but after he war they were booming. if you need an in-depth answer follow up with me  

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polar areas, such as antarctica or the south pole.

answer(c) carved on a babylonian clay tablet that showed earth as a flat circular disk;