White House spokesman Jay Carney says the FBI is conducting further tests to confirm the initial readings that the letters contained the poison ricin.

白宫发言人杰伊·卡尼表示，联邦调查局正在进行进一步的检测，初步检测结果表明信件中含有蓖麻毒素。

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Several hours after releasing the initial results, the plant operator said that those readings had been in error, and that retesting had shown negligible amounts of the isotope.

这一数据发布数小时后，核电站操作员对这些数据进行了澄清，重新检测后，只有微不足道的一些同位素被发现。

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The initial reports were the result of bad weather and faulty sonar and radar readings.

雷达声纳系统出错，加上天气恶劣，直接导致谬误报告的产生。

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So if it gets strong indications that organisms might be present, it will be able to subject samples to a wide range of tests to confirm initial readings.

BBC: Mars robots begin test campaign