Mr.Obama says it is necessary to end taxpayer bailouts of private companies and make financial deals more transparent.

VOA: standard.2010.04.24

And if the government didn't provide for the poor as ten percent as you say through taxation, then we would need more money for police to prevent crime and so, either way, there would be more taxes taken away to provide " what you guys call the necessary things that the government provides.

如果政府不能,通过税收来补贴你所提到的10%的穷人，则需要花更多的钱雇警力来防止犯罪,所以，不管怎样，都需要交更多的税,提供你们所说的政府该提供的“必需品。

耶鲁公开课 - 公正课程节选

He also explained that he thinks more troops are necessary to support the country's nascent police and military.

VOA: standard.2009.09.29

"It's absolutely necessary that we continue to push the envelope in terms of try to develop new innovative and more natural ways of effectively treating arthritis."

VOA: standard.2010.08.11

Their task is to find common ground, including on reduction of greenhouse gas emissions, promotion and transfer of new more eco-friendly technology and the necessary funding to make this possible, especially for the less developed and poorer nations.

VOA: standard.2009.12.08