Choose the correct options

1. You will never know who killed Mr Nilson
   [unless|if] you finish reading the book.
2. Billy, you should look up words in a dictionary
   [unless|if] you know them.
3. Hurry up!
   [Unless|If] we leave now, we won't catch the train.
4. Molly needs something.
   [unless|if] she talks to me now, she will not need to call me in the evening.
5. Megan why are you so slow? I will miss the bus
   [unless|if] you hurry up.
6. I want a new guitar, but I need $ 1,000 to buy it.
   [Unless|If] you lend me $1,000, I will buy a new guitar.
7. I need to pay for my classes. I will not get more money
   [unless|if] I work overtime.