1. we must leave now or we will miss the plane --> we will miss 2. She is faster and more careless driver than I am --> She drives 3. The car's so expensive that I don't think I can buy it --> It's su...

1 , We must leave now or we will miss the plane. –>  we will miss the plane If we don’t leave now.    

2, She is a faster and more careless driver than I am. –> She drives faster and more carelessly than I do.

3, The car’s so expensive that I don’t think I can buy it. –> It’s such an expensive car that I don’t think I can buy it.

4,How often do the mechanics service your car? –> How often do you have your car serviced by the mechanics?