All of which ensures that Sina will be extra cautious in how it polices its public square.

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With so much hype and investor interest in Facebook, Jacob says investors will need to be extra cautious.

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Firefighters across the park were told to be extra cautious.

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And Hadza women like symmetry in men's faces even more when they were pregnant or nursing, periods when they may be extra cautious about foods and disease harmful to a child.

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"The manager wanted to be extra cautious, " Boesch said.

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If you live on higher ground and your vehicle has thus far remained dry, be extra cautious when venturing out for the first time to avoid becoming submerged in standing or surging water.

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With used-car values already out of whack, shoppers need to be extra cautious to avoid compounding an already unfavorable financial situation by selecting a more problematic model that will require costly out-of-warranty repair work.

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