What is the grammatical function of "must have known" in the sentence: "Regulators must have known about the West Texas oil fields long before it became public"?

Question

Accepted Answer

It expresses logical certainty about a past event based on available evidence.

Answer

It expresses doubt about whether regulators had access to relevant information.

Answer

It expresses a missed opportunity to gain knowledge about the situation.

Answer

It expresses regret that regulators did not know about the oil fields sooner.

Crowdly

What is the grammatical function of "must have known" in the sentence: "Regulato...

Хочете миттєвий доступ до всіх перевірених відповідей на vo.uu.edu.ua?