The error here is "most thorough." Since "thorough" is followed by a verb it is an adverb, and thus must become "thoroughly." The correct way to write this would be "the most thoroughly researched." Adding the "-ly" to an adjective usually makes it an adverb, and every time and adjective is describing another adjective or a verb it must become an adverb. The "it" at the end is the correct pronoun, as "it" is referring to the paper.

This sentence uses the adjective “slow” to describe a the verb “were dimmed.” An adverb would be better. The corrected sentence reads: The lights were dimmed slowly, and the crowd gasped when the blue glow of the painted letters became apparent.

This sentence uses the adjective “previous” to describe the verb “seen.” An adverb would be better. The corrected sentence reads: The sharp beak and beady eyes of a common farm chicken can be terrifying to those who have never seen this animal previously.

"The best hunters" is the error here, making this a comparative error. The correct word would be "better" here because the sentence draws a comparison between two groups—females and males. Whenever a comparison is drawn between two items, it is correct to use the "-er" form of the word; this is known as the "comparative" form of the word. Whenever a comparison is drawn between three or more things, you use the "-est" form of the word, known as the "superlative" form. A comparison is used to compare one item to one other item; superlatives are used to distinguish one item from many other items.

In this sentence, the adjective “excruciating” is used to describe the other adjective “detailed.” Adverbs should describe adjectives, so the adverb form “excruciatingly” would be better. The corrected sentence reads: My mother explained the process to me in an excruciatingly detailed manner; you don’t need to worry about me forgetting anything.

In this sentence, the adjective “graceful” is used to describe the verb “danced.” Adverbs, not adjectives, should describe verbs, so the adverb version “gracefully” would be better. The corrected sentence reads: The kite caught the breeze, flew up in the air, danced gracefully about the sky, and lodged itself in a tree.

The correct adverb here would be among, because there are multiple kittens in a litter, not just two.

In this sentence, the adjective “actual” is used to describe the verb “connected.” The adverb should be used instead. The corrected sentence reads: The scapula are not actually connected to the rib cage through any bones or joints.

The underlined portion of the sentence uses an adverb "lately," where an adjective should be used. The only answer choice that properly uses an adjective is "later than expected," which is the correct answer choice.

The word proud needs to be an adverb because it is modifying looked.