Which best identifies the tense of the verb have known?
a. future perfect
b. past
c. past perfect
d. present perfect

postive, comparative, superlative - good, better, best

recall how we defined nouns as words capable of having plurals and possessive endings. adjectives (and their first cousin, the adverb) also have a feature that distinguishes them. they come in three states. first, the raw adjective—in its positive state—merely describes the noun modified; it doesn’t care about how this particular person or thing stacks up against other members of the same noun class

sir, we have done everything that could be done to avert the storm which is now coming on" is the sentence that best articulates this. then he gives the examples.   mark me brainliest

op: object of preposition