documentclass[twocolumn]{article}
usepackage[fontsize=12pt,baseline=14.4pt]{grid}
usepackage[top=25mm, bottom=25mm,left=40mm, right=25mm]{geometry}
setlength{columnsep}{20pt}
usepackage{ragged2e}
usepackage{blindtext}
usepackage{setspace}

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begin{document}
section{Blah! Blah!}
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begin{quotation}
noindent This is direct, displayed quotation or verbatim word-to-word copy from referenced material, when I am too lazy to paraphrase. This is done when the words exceed 40 words or so, but bfseries{I want this to be singlespaced}.
end{quotation}
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section{Another Blurb}
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begin{gridenv}
begin{eqnarray}
frac{sum^X_Y}{prod'_C} = x'' + y^{2} + z_{i}^{n}label{eq1}\
frac{int^sum}{int_prod'} = x'' + y^{2} + z_{i}^{n}label{eq2}
end{eqnarray}
end{gridenv}
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end{document}