1.you should apologize for the misunderstanding to her
→ If we're you........
2: If she doesn't change her mind ,i'll never talk to her again
→unless she.  .....
3:we don't visit our grandparents very often because thay live far from us
→if
4: people use too many cars for transportation.That's why the environment is seriously polluted
→ if 
5:she is shy,so she doesn't enjoy parties
→if
6: you can't make a cake without flour
→if
7:you should take exercise because that's the way to keep fit
→if
8:I don't know anything about the story so i can't tell you how it ends
→if
9: the wind is blowing hard,so we won't take the boat for a ride
→if
10: don't leave the TV on if you aren't watching ít

→unles