The first lesson of Enduring Freedom is that it is impossible to know with certainty when and where new challenges will arise.

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"When you drive and you see another car on the track it is almost impossible to notice details, from whatever car, " said Vettel.

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When you do the math, it is impossible to ignore the disproportionate number of women and minorities who are currently unemployed.

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How that happens may be impossible to pin down, but you know it when you see it, and it is inspirational, it is emotional.

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This is most noticeable when you're viewing darker screens, and while it doesn't make it impossible to enjoy movies and YouTube clips on the tablet, it does separate the Excite 10 from higher-end slates.

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Most loggers harvest when the land is frozen, but a run of mild winters has melted the logging roads and made it impossible to harvest the wood without scarring the land which, in turn, gives environmentalists more cause for complaint.

ECONOMIST: The logging industry

When the source material is ultrafamiliar and the original film full of top-tier stars, it's all but impossible to survive the comparison game.

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When I removed the dough from the bowl, I found it stiff and nearly impossible to knead by hand, which is what the recipe called for next.

WSJ: Delicious Babka With Nutella