Directions: Each of the following items features one part of a sentence, followed by four alternatives. Complete the sentence by choosing the correct alternative. We must wait

Step-by-step solution

The sentence requires a conjunction of time to indicate the duration of waiting. "Until" is the most appropriate and formal conjunction here, meaning "up to the point in time or the event mentioned". The phrase "see the light turn green" correctly uses the bare infinitive "turn" after the verb of perception "see". Therefore, the most grammatically correct and idiomatic completion is "until you see the light turn green". Answer: until you see the light turn green