The U.S.Federal Bureau of Investigation and other federal law enforcement agencies are providing assistance to Mexican authorities in this investigation, but they have declined to comment on the developments in Mexico.

VOA: standard.2010.04.01

That means that they've never declined as much in one month before; our data started in 1987.

那意味着它们从来没有在,一个月之内下降过这么多；,我们从1987年就开始记录数据了。

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