Complete using the correct form of the verbs in brackets

Ex6. Complete using the correct form of the verbs in brackets.
1. Stop talking or you won’t understand the lesson
=> If________________________________________________
2. I don’t know the answer, so I can’t tell you.
=> If________________________________________________
3. We got lost because we didn’t have a map.
=> If________________________________________________
4. Without this treatment, the patient would have died.
=> If________________________________________________