Correct Answer: A

Rationale: The comma after 'think' is unnecessary and incorrect. It should be removed to correct the sentence. The semicolon after 'do' is correct as it separates two independent clauses. The period at the end of the sentence is necessary to indicate the end of the sentence. The comma after 'and yet' is correctly used to separate two independent clauses joined by a coordinating conjunction.

Correct Answer: B

Rationale: The correct answer is B: 'The cat sat on the mat after it ate.' 'After it ate' is a dependent clause because it cannot stand alone as a sentence. It is dependent on the main clause 'The cat sat on the mat.' Choice A is a simple sentence without a dependent clause. Choice C is a sentence with a time adverbial modifying 'The cat will sit on the mat,' not a dependent clause. Choice D is a sentence in the present continuous tense, also lacking a dependent clause.

Correct Answer: B

Rationale: The correct answer is B. Parallel structure ensures that items in a series or list are in the same grammatical form. In choice A, 'to run' disrupts the parallel structure since 'hiking' and 'swimming' are gerunds. Choice C similarly breaks the parallelism by using 'to swim' in a different form. Choice D is incorrect because it lacks consistent parallelism, as 'hiking' is not followed by gerunds like 'swimming' and 'running.' Therefore, only choice B maintains proper parallel structure by using gerunds ('hiking,' 'swimming,' and 'running') consistently.

Correct Answer: D

Rationale: In this sentence, 'increasingly' is functioning as an adverb. Adverbs modify verbs, adjectives, or other adverbs to describe the manner, degree, or frequency of an action. In this case, 'increasingly' describes how the difficulty of the hike was growing as we approached the mountain top. Choice A, 'Adjective,' is incorrect as adjectives modify nouns or pronouns, not verbs. Choice B, 'Interjection,' is also incorrect because interjections are words used to express strong emotions or sentiments, not to describe actions or qualities. Choice C, 'Verb,' is incorrect as 'increasingly' is not a verb; it does not express an action or state of being.

Correct Answer: A

Rationale: The correct answer is A: 'The plump, old, white cat basked in the warm sunlight.' Commas should be used to separate coordinate adjectives describing the cat. In this sentence, 'plump,' 'old,' and 'white' are coordinate adjectives, each providing distinct information about the cat. Option B incorrectly places a comma after 'white,' creating a nonessential element. Option C lacks commas to separate the coordinate adjectives. Option D incorrectly places a comma after 'cat,' causing a punctuation error.