The answer is nearly four centuries ago - December 21, 1638.

答案是近4个世纪以前——1638年12月21日。

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The film was released in the United States and Canada on December 21, 2007.

该片于2007年12月21日在美国和加拿大上映。

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Later this year Jupiter and Neptune will meet again - July 10 and December 21.

今年迟些时候，木星和海王星会再次产生合相- 7月10号和12月21号。

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The decision to release him early from prison elicited a firestorm of condemnation from many American family members of victims of Pan Am flight 103, which blew up over Lockerbie on December 21,1988.

VOA: standard.2009.08.21

Some people believe the Mayan Calendar is forecasting Armageddon to start on December 21, 2012.

FORBES: Look out! 'Tis the Season for Predictions

The consumer electronics retailer has also begun promoting free online shipping on purchases made through December 21.

FORBES: Retailers Roll Out Gimmicks to Lure Holiday Shoppers

These are timely questions because December 21, 2012 is the day that time is scheduled to end.

FORBES: Resolute About Resolutions