Choose the correct options.

1. [If|Unless] you fall, you might get injured.
2. You can't be a professional sportsman
   [unless|if] you have professional equipment.
3. [Unless|When] you feel exhausted, don't do any physical activities.
4. I wouldn't have joined this club
   [unless|if] I hadn't liked football.
5. The competitors start the race
   [unless|when] they hear the signal.
6. [If|When] you don't train, you won't get good results in any sport.
7. I won't win the tournament
   [unless|if] I get stronger.
8. [Unless|When] it rains, we'll help to clean up the park.