They will prevent sickness, help you feel better and may even save your life.

VOA: special.2010.07.27

They help prevent fraud, misrepresentation, manipulation of information in stocks and bonds.

它帮助人们防止诈骗，虚报和巧妙利用证券股票市场中，信息不对称而牟利等事情的发生。

耶鲁公开课 - 金融市场课程节选

Moreover they can also borrow from the Federal Reserve Banks when they're in trouble and need money and that's supposed to help prevent banking crises.

更多的是，当它们陷入困境,需要钱时可以,从联邦储备银行那里借钱,这样可以帮助阻止银行业危机的产生。

耶鲁公开课 - 金融市场课程节选

They also help prevent soil loss and protect water supplies.

VOA: special.2009.09.01

But they noted that some do help to prevent disease.

VOA: special.2009.04.21