Weegy: The Milky Way is held together by a black hole's gravitational force. Since the stars near this black hole move at a high speed, you can infer the black hole's SIZE.
User: What are the two types of variable stars?
Weegy: The two types of variable stars are: intrinsic and extrinsic variables.
User: Which of the following statements about the tail of a comet is correct?
Weegy: A comet is an icy small Solar System body that, when passing close to the Sun, heats up and begins to outgas, displaying a visible atmosphere or coma, and sometimes also a tail.
User: Look at the figure above. Which layer of the sun produces energy that reaches the earth?
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