Ответ:
1) Einstein was a scientist. He was very clever and discovered (discover) the theory of relativity.
2) Gagarin was a austronaut. He was the first person who flew (fly) to the Space on the spaceship “the East”.
3) Shoqan Ualikhanov was an traveler. He wasn't travelled (not travel) to Australia but he travelled around Central Asia.
4) Christopher Columbus was a seafarer (мореплаватель). Was he swam (swim) between India and Europe?