The U.S. Government also issues small denomination debt to individuals to help them called savings bonds, but we aren't talking about those.

美国政府也发行小面值债券,用于面向个人,叫做长期储蓄债券,我们今天不涉及这些

耶鲁公开课 - 金融市场课程节选

Bonds sold off from the start of trading, and the selling accelerated after Moody's Investors Service said that the U.S. sovereign-debt could be negatively affected by the extension of tax cuts and if the government can't get its growing debt under control.

WSJ: Tax-Cut Deal Results in Turmoil for Bonds

The yield on long-term (10-year) government debt hasn't really fallen since the last batch of QE was announced in October, but since July 2011 the government's cost of borrowing has fallen by around 1 percentage point, from just over 3% to just over 2%.

BBC: Quantitatively more easing from the Bank

He pointed out that China has been increasing its holding of euro-denominated government debt and hasn't been selling since the risk of a Greek default became acute.

BBC: Chinese Premier backing the euro and the UK