But nothing blesses those who, like Simon Legree, employ such slaves but can't be bothered to tell them apart.

ECONOMIST: Johnson

And he needed to be able to tell them apart as precisely as possible, to avoid recording two arrivals as one.

ECONOMIST: Small-scale physics

My little brother even raised eight baby possums after their mother was hit by a car (all named Henry, so it was hard to tell them apart).

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How do you tell them apart?

NPR: Excerpt: 'Delivered from Distraction'

Can you tell them apart?

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The stock fell to an eight-year low after RIM announced that it would have no new BlackBerry models until late 2012 and, according to analysts, the problem with the current line-up is that there are so many models and features, nobody can clearly tell them apart.

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The researchers then trained a new group of rats to discriminate between the odours the first animals could not tell apart by rewarding them over and over with sips water for choosing the appropriate hole.

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