If I don't leave now, I'll miss my train.
=> Unless I leave now, I'll miss my train.

5. I won't be able to do anything unless I have a quiet room.
=> If I don't have a quiet room, I won't be able to do anything.

6. Children take part in many after-school activities when school finishes.
=> Children do many after-school activities when school finishes.

7. Do you think money is more important than any other things in the world?
=> Do you think money is the most important thing in the world?

8. Do you have a better refrigerator than this?
=> Is this refrigerator better than yours?

9. How many classes are there in your school?
=> How many classes does your school have?

10. I like coffee. My father hates it. (but)
=> I like coffee, but my father hates it.