GMAT Sentence Correction (SC) | Re: Several Pentagon contractor firms are working on a new class

prepare
outbreaks of dangerous viruses
still another growing threat
the accidental releases of nanoparticles,
are the infinitesimal, engineered fibers that are starting to be used in electronics, food, medicine, and more.

Categorize them into different tiers

Prepare : outbreak
Threat
________ =accidental release of nanoparticles

__________= fibers

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