PLANETS' CROSSWORD

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Across
  1. 2. The closest planet to the Sun
  2. 4. The coldest planet
  3. 5. Space traveler
Down
  1. 1. Contagious substances that kill the planet
  2. 2. It is a planet in which there is also water
  3. 3. The planet that is between Mercury and the Earth
  4. 6. Vehicle that flies through space