Question

1. choose the best answer.

what is a galaxy?
○ it is a system including the sun and all the objects that orbit it.
○ it is the space beyond the solar system.
○ it is a system of millions to billions of stars, dust, and gas clouds.
○ it is a large round body that orbits a star, does not orbit anything else, and has a clear orbit.

Explanation:

To determine the best answer, we analyze each option:

• Option 1 (It is a system including the sun...): This describes a solar system, not a galaxy.
• Option 2 (It is the space beyond the solar system): This is too vague and does not define a galaxy.
• Option 3 (It is a system of millions to billions of stars, dust, and gas clouds): This matches the definition of a galaxy, which is a massive system containing stars, interstellar matter (dust, gas), etc.
• Option 4 (It is a large round body that orbits a star...): This describes a planet.

Answer:

The second option (from the left, with the text "It is a system of millions to billions of stars, dust, and gas clouds")