Choose the correct answer

Which of the following sentences is correct?
1. The Milky Way is a nebula formed of dust and gas
2. The Milky Way is the galaxy where we are and the Solar System is at its centre
3. The Milky Way is the galaxy to which the solar system belongs
4. The milky Way is the closest galaxy to ours
Which of the following sentences is correct?
1. The Solar System constitutes the universe
2. The Earth is at the centre of the universe
3. Our galaxy is just one of the billions or trillions that make up the known universe
True or false: The comets move into a orbit
1. True
2. False
How do we call the Earth´s movement around the Sun?
1. Rotation
2. Orbit
3. Revolution
4. Comet
The Earth´s satellite is called....
1. the Moon
2. the revolution
3. the Halley comet
4. the Sun