Ответ:

  1. We saw the window open.
  2. We heard one of the students in the gym talk to Ann.
  3. Mother made her daughter stay at home.
  4. Don’t let your children climb that old tree.
  5. The dog ran after the cat and saw it climb a tree.
  6. The professor watched Eliza working in the study.
  7. They laughed when they heard him singing so loudly.
  8. I’ve never heard him speak Italian.
  9. The children watched the monkey eating a banana.
  10. We heard the lion roaring.