Generally, there are a couple of elements that one might set down as in a Petri dish, and wait to see if some chemical reaction might take place, but not at all sure of what it might be.

一般来说，都有几个元素,作者会把它们像放入培养基中一样培养,等待某种化学反应的产生，但对可能的结果却一无所知。

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Back in the lab, he places plant bits in petri dish cultures, coaxing endophytes to grow.

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At almost every juncture, there has been a festering petri dish of sociological behavior to study.

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Mr Newsom has tried to turn it into a Petri dish for new-media and biotech companies.

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