Ответ:

  1. I need to clean my room. It’s so untidy.
  2. He’s bad at Physics. For him it’s an impossible subject.
  3. She dislikes fish. She prefers chicken.
  4. It’s very impolite to ask how much they earn.
  5. As soon as we arrived at the hotel, we unpacked our suitcases.
  6. He was unemployed for two years but then he found a good job as a gardener.
  7. “I think playing computer games is boring.” — “I disagree. In my opinion, it’s interesting.”
  8. Of all sisters you make me do all the house chores! It’s unfair!
  9. It’s illegal to sell alcohol to children and teens.
  10. The thief stole the woman’s bag, ran out from the café and disappeared.

Приставки образуют слова с противоположным или отрицательным значением: un-, im-, il-, dis-.