Watson and Crick described it well in their published work on DNA and its structure. ... This understanding of the structure of DNA is particularly important because it led to the realisation that if there is an adenine on one side of the pair, then the other base must be thymine.
The best answer is:
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[C]: <span> "It comes from many sources rather than from a particular site."
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However, "non-point source pollution" could come from one source, but not be located from one specific site.
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