Xinhua: U.S. President George W. Bush said on Wednesday that the United States must strongly push forward the development of renewable energy sources in order to reduce its dependence on foreign oil. "America has got to change its habits. We’ve got to get off oil," said Bush when he addressed the Washington International Renewable Energy Conference (WIREC). "Dependency on oil presents a real challenge to our economy," said Bush. It also presents a challenge to the …