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.