Which sentence contains an error in how its third-conditional if-clause treats an unreal past?
If the curator had checked the crate, she would have spotted the crack.
If the crew would have secured the awning, it would have remained in place.✓Correct answer
If the beekeeper had worn thicker gloves, she would not have been stung.
If the board had reserved a larger room, everyone would have found a seat.
Explanation
The crew sentence is erroneous because would have secured appears inside the if-clause. That clause needs the past perfect, while the result may correctly use would have remained.