Question

1. match the terms with the definitions.

the distance that light can travel in one year, or 9.5 trillion km
the system including the sun and the natural objects that orbit it
a large round object that orbits a star, does not orbit anything else, and has a clear orbit
a system of millions to billions of stars, dust, and gas clouds
a natural object that orbits a planet

Explanation:

• Galaxy: A system of millions to billions of stars, dust, and gas clouds.
• Solar system: The system including the sun and the natural objects that orbit it.
• Planet: A large round object that orbits a star, does not orbit anything else, and has a clear orbit.
• Moon: A natural object that orbits a planet.
• Light - year: The distance that light can travel in one year, or 9.5 trillion km.

Answer:

galaxy - a system of millions to billions of stars, dust, and gas clouds; solar system - the system including the sun and the natural objects that orbit it; planet - a large round object that orbits a star, does not orbit anything else, and has a clear orbit; moon - a natural object that orbits a planet; light - year - the distance that light can travel in one year, or 9.5 trillion km.