Detailed Instructions: Given two noun phrases (arguments) and relationship between them, form a sentence that expresses theses arguments with the given relationship.
Q: Relationship: 'be chairman of', Argument/Subject 1: 'bernanke', Argument/Subject 2: 'federal reserve'
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
US Federal Reserve chairman Ben Bernanke has said an economic stimulus alone will not be enough to promote a lasting recovery and that further steps to help banks may be needed .