0. The Earth (travel) travels around the Sun in 365 days. 1. The Uranus (discover)
in 1781 by a British
astronomer Willian Herschel.
2. People (search)
conditions for life on other planets
now.
3. It take)
165 years to travel around the Sun for Neptune.
4. People (call)
Mars the red planet.
1. discovered
2. searching
3. takes
4. calling