Fill in the blank (sequence with “before”) “The pilot had been warned about the storm, before he ______.” Choose the verb form that creates a correct time sequence.

Given data

• Past warning precedes the action of departure.

Concept/Approach
Use simple past for the later action and past perfect for the earlier state: “had been warned … before he took off.”

Option analysis
took off — correct; follows the past-perfect clause.had taken off — would mean the takeoff happened even earlier, which clashes with “before he …” here.was taking off — progressive aspect is unnecessary and awkward.has taken off — present perfect does not match a past-time narrative.

Final Answer
took off