I should point out to date, very little actually has been, but there is certainly fears that more could be at some point and that could mean very serious shortages of oil.

我应该指出，到目前为止，实际上只有很少的石油退出世界市场，但肯定有人担心，在某个时候可能会有更多的石油退出，这可能意味着非常严重的石油短缺。

Daniel Yergin wrote a book called " The Prize, " which is a history of the oil industry. He says the increase in U.S. production helped avoid a severe shortage of oil that would have caused prices to rise even higher.

丹尼尔·叶尔金写了一本书，名叫《石油大博弈》，是一本关于石油工业的历史书。他说，美国石油产量反弹有助于避免全球因石油严重短缺而造成的油价大幅上涨。