No single country owns Antarctica. Instead, 54 countries have signed the Antarctic Treaty, which designates Antarctica as a scientific preserve open to all nations for peaceful research.

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Currency exchange rates are prices that show how much of one currency you need to buy another currency, determined by supply and demand in global markets. Banks, businesses, and traders buy and sell currencies constantly, which causes exchange rates to change throughout each day.

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The International Date Line is an imaginary line on Earth's surface that runs roughly along the 180th meridian in the Pacific Ocean, where the calendar date changes by one day. When you cross it traveling west, you move to the next day, and when traveling east, you move back one day.

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Antarctica is the largest desert on Earth, covering about 5.5 million square miles. It is classified as a desert because it receives very little precipitation, mostly in the form of snow.

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Vatican City is the smallest country in the world, covering only about 0.17 square miles (0.44 square kilometers). It is an independent city-state located entirely within Rome, Italy.

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