Canada began its nuclear program as early as 1944 and built its first experimental reactor in 1947.

加拿大早在1944年就开始了核项目，1947年它建造了第一台试验性的核反应堆。

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Sales in stores began on Friday in Japan, Australia, France, the U.K., Germany, Canada and the United States.

iPhone 4s于上周五开始在日本、澳大利亚、法国、英国、德国、加拿大和美国的苹果专卖店内销售。

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A cold summer in Canada and the United States in 2009 meant that the following winter saw fewer monarchs in Mexico than at any time since records began in 1994.

在2009年，因为加拿大和美国那个寒冷的夏天，冬天来到墨西哥的帝王蝴蝶创下了自1994年有记录以来最低水平。

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Fifty-plus countries are represented at this second annual global conference, which began four years ago in Canada.

FORBES: Global Terrorism And The World Conference Of Women In Washington, D.C.

As political scientist Nelson Wiseman explains, public support in Canada began to drop.

NPR: Afghan Leader Wants Canada's Troops to Stay

The Agriculture Department confirmed the first case of mad cow disease in America on December 23, 2003, in a cow born in Alberta, Canada, in April 1997, only four months before the United States and Canada began banning the use of brain and spinal cord tissue in cattle feed.

CNN: USDA quarantines 2 farms in mad cow investigation