Đáp án : Had you not come , they wouldn't have been able to complete the mission .

`@` Câu điều kiện diễn tả hành động không có thật ở quá khứ .

`=>` Điều kiện loại `3` : If + S + had + V3/Vpp + O , S + would/modal verbs + have + V3/Vpp + O .

`=>` Đảo ngữ : Had + S + V3/Vpp + O , S + would/modal verbs + have + V3/Vpp + O .

`\color{#145277}{N}\color{#246483}{a}\color{#34768F} {e}\color{#44889B}{u}\color{#539AA7}{n}`

`=>` Had you not come, they wouldn't have been able to complete the mission .

`------`

`@` IF `3` : IF + S + had + V3/ed, S + would / could / might / `...` + have + V3/ed

`@` Đảo ngữ IF `3` : Had + S + V3/ed, S + would / could / might / `...` + have + V3/ed