The traditional approach with complex problems is to break them down into smaller,more easily managed problems．

A sh<u>oo</u>t   B bl<u>oo</u>d   C r<u>oo</u>f    D t<u>oo</u>l

A do you B will you C can we D shall we

A Only if； you will B Only if； will you C Unless； you will D Unless； will you

A is made of B is composed of C is consisted of D composed of<br/>

A remained B lived C endured D survived<br/>

A consist B persist C insist D resist

A What B That C Which D As

A of them B whose C their D with whom<br/>

A called off B called up C called in D called on<br/>

A can B must C should D would<br/>