Question

Resourcefulness is the key to overcomr problem ( convert this sentence into complex)

Answer 1

Given sentence :  
     Resourcefulness is the key to overcome (the/a) problem.

Conversion into Complex sentence:
     Resourcefulness is the key, if you want to overcome (the/a) problem.
     Resourcefulness is the key, if we have to overcome (the/a) problem.

There could be some other correct answers too.  Some other conjunctives may be used to form different complex sentences.