1 - The trains all would stop if it snowed heavily.
2 - If you went out in cold weather without a coat, you would catch a cold.
3 - If I saw a cheap second-hand car, I would buy it.
4 - If you ate well and exercised regularly, you would live100 years.
5 - You would have had stomach ache if you had eaten too much of that cake.
6 - If it rains this afternoon, I will take my umbrella.
7 - If you did not drive carefully, you would have an accident.
8 - If you study for a higher qualification, you will get a better job next year.
9 - If you sent the letter by first class mail, it would get there the following day.
10 - If the weather is fine, we will go for a picnic.

1. stop
2. went out
3. went buy
4. would live
5. had eaten
6. rains
7. would have
8. stady
9. would get
10. will go.