The project __________ by the deadline, thanks to the team's hard work.
Q1. The project __________ by the deadline, thanks to the team's hard work.
Answer: was completed
Explanation: 'was completed' correctly uses the simple past tense in passive voice to describe a completed action by a specific time in the past. 'had been completed' fails because it implies the action was completed before another past action, which isn't the case here.