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Help Dr. Frankenstein's meticulous assistant complete the laboratory evaluation report by selecting the correct words.
While evaluating the glowing green sludge, Igor noted that _________________________ bizarre _________________________ was highly unstable, and that only a small _________________________ of the safety _________________________ had been met.
this / phenomenon / number / criteria
this: The verb "was" is singular, so we need the singular demonstrative determiner "this".
phenomenon: This is the singular form of the noun (of Greek origin). "Phenomena" is plural, and "phenomenons" is incorrect.
number: Because the following noun is countable, we must use "number" rather than "amount" (which is for uncountable nouns).
criteria: This is the plural form of "criterion" (Latin origin). Since we are talking about a "number of" them, it must be plural.