Dr. Aris is trying to avoid getting her paper rejected by a notoriously strict science journal. Select ALL the grammatically correct sentences she can use.
The correct answers are These criteria are essential for understanding the anomaly. and Much research has been conducted on this bizarre phenomenon.
"Criteria" is the plural form of the singular noun "criterion". Therefore, it must be paired with the plural demonstrative determiner "these" (not this).
"Phenomenon" is singular (plural: phenomena), so it correctly takes "this".
"Research" is an uncountable noun in English; it cannot be made plural (researches) and must be quantified with "much" rather than "many".