Viết lại các câu sau

we haven't got any matches, so we can't light a fire.
-) if   
I can't give you a ride because I don't have a motorbike
-) If
she  goes to shool late because she lives far from school
-) Unless she lived
David has so many accidents because he's so clumsy
-) If David
I'm so busy, so I don't write to my friends regularly
-) If I
we can't buy this car because it is very expensive
-) If this car