But a study of elderly patients discharged from a hospital's intensive care unit (ICU) shows that almost 40 percent did not survive beyond the research period of three years.

VOA: standard.2010.03.07

Why this period as a unit?

为什么这段时间被分成一个时间单元

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After contracting Lyme disease in 2010, Ms Drew was frequently out of the office for a critical period, when her unit was making riskier bets, and her absences allowed the clashing egos of her subordinates to come to the fore.

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Unit shipment growth from 2006 through 2010 was about 50% and roughly 12% annually over that period with some significant hits in unit growth in 2008 and 2009, due to the most recent recession.

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During the nasty 2009 slump, the smartphone market was so young it grew through the period of overall handset market unit decline.

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