GK
THE UNIVERSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a star and it’s surrounding planets
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billions of stars held together by gravity
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the big bang
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a cluster of nebulas
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Detailed explanation-1: -Our galaxy, the Milky Way, is typical: it has hundreds of billions of stars, enough gas and dust to make billions more stars, and at least ten times as much dark matter as all the stars and gas put together. And it’s all held together by gravity.
Detailed explanation-2: -A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
Detailed explanation-3: -Earth is part of the solar system, which is part of a galaxy, which is part of a galaxy group. All of these systems are held together by gravity, a force that pulls objects with mass toward each other.
Detailed explanation-4: -A star is a sphere of gas held together by its own gravity. The closest star to Earth is our very own Sun, so we have an example nearby that astronomers can study in detail.