Ответ:

  1. It stopped raining for a while, but now it’s raining again.
  2. The town where I live is very different now. It has changed a lot.
  3. I studied German at school, but I have forgotten most of it now.
  4. The police arrested three people, but later they let them go.
  5. What do you think of my English? Do you think it has improved?
  6. Are you ready to go? Have you finished your coffee?
  7. I applied for a job as a tour guide, but I wasn’t successful.
  8. Where’s my bike? It was outside the house, but it’s not there now.
  9. Quick! We need to call an ambulance. There has been an accident.
  10. A: I’ve found my phone.
    B: Oh, good. Where did you find it?
    A: It was at the bottom of my bag.
  11. A: Ben won’t be able to play tennis for a while. He has broken his arm.
    B: Oh. How did that happen?
    A: He fell off a ladder.

Present perfect is used for past events connected with the present; past simple is used for finished events at a definite past time or in a completed past situation.