She says people must keep up their guard against the virus, which is unpredictable and could change into a far more dangerous form.

VOA: standard.2009.12.29

Language has powers that are entirely unpredictable, that can't be harnessed in precisely that deliberate way: by making a decision to take someone's words in the wrong way, or by telling a story to make a moral point, as the mother does.

语言的力量无可估量，绝不是单单使用一下那么简单：,而是通过假意遵从，以及勾起人性良知的方式表达的。

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Clearly, it is not as potent and unpredictable a force as it was in 2010.

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In Dar es Salaam in Tanzania electricity is on only for two unpredictable hours a day.

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The other reason, possibly linked to the first, is that a series of unpredictable results has produced a midterm points table that bears little resemblance to anything anyone expected.

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