Answer:
Question 1
The correct answer is A. The fireworks show will start after the sun goes down.
An adverbial clause according to quiz-let, is "a dependent clause that modifies a verb, adverb or an adjective". It starts or ends with "subordinate conjunction". Examples of subordinate conjunctions are, unless, because, after, until, till, if, when, since, as, given, etc. An adverbial clause can relate to time, purpose, condition, manner among others. From the sentence above, the word "after" is a subordinate conjunction.
Question 2
The correct answer is D. Both Amy and Marnie received ten dollars for washing their mom's car.
A subject-verb agreement involves the agreement of both a subject and a verb in a sentence. This technically means that the subject must always come before the verb. The subject should have a pronoun or noun while the verb singular or plural.
From the above sentence, "Amy and Marnie " are the subjects while "washing" is the verb.