Question: If we hadn't stayed up so late last night, we _____ the flight this morning.
Correct Answer: wouldn't have missed
This question tests the third conditional (past unreal conditional) structure. The correct answer uses "wouldn't have + past participle" to show a hypothetical result in the past (missing the flight) that didn't actually happen because of an unreal past condition (staying up late).

Incorrect Answers:
- wouldn't miss - Uses present conditional, but the situation refers to a past event
- won't miss - Uses simple future tense, but the situation is hypothetical and in the past
- won't have missed - Mixes future perfect with a past conditional context