美国官员正在密切关注俄罗斯的一起事件，上周有一名女性死亡。当局称她曾在一家研究鼠疫的实验室工作。NBC新闻的Anne Thompson报道。
U.S. officials are closely monitoring a situation in Russia after a woman died last week. Authorities say she worked at a lab that studied the plague. NBC News’ Anne Thompson has the story.