Fill in with if or unless.
1 ..... the shoes fit, i will buy them.
2. She won't go to work tomorrow ............. she is feeling better.
3. ............ you finish your homawork quickly, we will watch a DVD.
4. .......... you run Fast, you'll miss  the train. 
5. .......... i see Nigel, i'll tell him ti send you an email.
6. Don't do the washing-up ...... you want to.