"Keeping track of everything is an arduous task, and there's never been a clear system, " he said.

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Crooke's first task, an arduous one, was to find out how big the drug should be to best target RNA. RNA strands stretch thousands of nucleotides long, and there may be only one offender out of 100, 000 different strands floating in a cell at any given time.

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In Iraq and Afghanistan, fighting an enemy that has deliberately exploited America's military and political weaknesses has proven to be an arduous task.

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