Ответ:

1. If you see a bat in the cave, don't try to catch it!

2. If we go to London, we can visit Big Ben.

3. We will buy a car next year if we will have the money.

4. If Nancy doesn't want to go to the concert, she can stay at home.

5. Ask the teacher if you don't understand something.

6. If you break anything in the shop, you must pay for it.

7. If you are quiet, the baby will sleep.

8. If you want to help protect the environment, you must throw your rubbish in the bin.