4. Unless someone waters them, those flowers will die
5. Unless he tells the truth, no one can help him
6. If you don't keep your feet dry, you will catch a cold
7. Unless I catch the plane, I won't be ho,e by five
8. Unless you apologize, I will never speak to you again
9. If he doesn't give me his number, I won't phone him
10. Unless he learns his lesson carefully, he can not do that exercise
