1. The trains ((stop)) if it (snow) heavily. 2. If you (go) out in cold weather without a coat, you (catch) a cold.
3. If I (see) a cheap second-hand car, I (buy) it.
4. If you (eat) well and (exercis) regularly, you (live) 100 years.
5. You (have)stomach ache if you (eat) too much of that cake.
7. If you(drive) carefully, you (have) an accident.