Choose the best answer A, B, C or D.
1. Many efforts have been made to _________ the environment.
2. _________ is a great source of energy but very dangerous.
3. The number of rare animals is decreasing ________ rapidly that they are in danger of becoming extinct.
4. The knife _________ we cut bread is very sharp.
5. There are also other hobbies that I _________ in for a while.
6. Scientists are always looking for new _____________ of energy.
7. Yuri Gagarin was the first ___________ in space.
8. Solar energy is not only plentiful but also infinite.
9. Many spacemen could never get back to the Earth because of ____ accidents.
10. He finds it difficult for him to recover from his son’s ____.
11. A / an ____ is a person who is trained for traveling in a spacecraft.
12. When spacemen travel into space they have to face enormous ____ because they do not know what may happen.
13. _________ from all over the world take part in the Olympic Games.
14. Human being have great _________ on the rest of the world.
15. The singer was ___________ on the piano by her sister.
16. “I’m sorry I’m late. I missed the bus.” – “________. We haven’t started yet.”
17. Lisa’s been able to play the flute since she was six, ____?
18. Jenny ____ leave the hospital only fours days after the operation.
19. Neil Armstrong was the first man to set foot on ____ moon.
20. Everybody congratulated the astronauts ____ their successful trip into space.
