TOEIC Reading 5 Exercisee 251

<p>Let's analyze the sentence:<br></p><p><strong>People (who arrive more than 30 minutes ____ the opera begins)&nbsp; should wait in the lobby until the doors to the main hall are opened.</strong><span><span style=""><br></span></span></p><p>This sentence is a complex sentence with the main clause and the adverb clause.&nbsp;The main clause is&nbsp;"People who arrive more than 30 minutes ____ the opera begins&nbsp; should wait in the lobby". The adverb clause is "until the doors to the main hall are opened".<br></p><p>There is an adjective clause “who arrive more than 30 minutes ______ the opera begins” before the noun "People".&nbsp;</p><p dir="ltr" style="text-align: justify;"><span><span style="">Let’s focus on the adjective clause “who arrive more than 30 minutes _______ the opera begins.” The blank should be filled with a subordinating conjunction to connect "who arrive more than 30 minutes" and "</span></span>the opera begins."</p><p dir="ltr" style="text-align: justify;">The correct answer is (B) before. In this sentence, the phrase "more than 30 minutes" indicates a specific time period. The word "before" is used to indicate that the arrival should occur prior to the opera beginning. This makes the most sense in the context of waiting in the lobby until the doors are opened.&nbsp;</p><p dir="ltr" style="text-align: justify;">Thus, choice (D) during is incorrect since it is a preposition, not a subordinating conjunction. choice (A) and (C) are subordinating conjunctions, but they do not make sense here.<br></p>