I.
1. Unless he takes more care, he'll have an accident.
2.unless it rains soon, the crops will be ruined.
3.if the weather isn't fine, we'll stay at home.
4.if I don't get my work finished, I can't go with you.
5. Unless you leave on the 15°,you'll get home late for your mother's party.
6.if Tom's father doesn't tell him what to do, he never does anything.
7.unless you really want this job, don't take it.
8. unless she does something to prepare for the test, she will get bad marks.
9.if you don't get a visa, you can't visit the Unites States.
10.if you don't remember your address, you can find it in the phone book.
II.
1. If my brother had enough money, he wouldn't buy that car.
2. if it didn't rain, we could go out.
3.if I knew his address, I could contact him.
4. If it weren't too cold, we could go swimming.
5. If the exercises were't very difficult, I could finish in fifteen minutes.