TOEIC Part 5 練習問題 P5_207
------- the proposal had been approved earlier, the project would have been completed by now.
✅ 正解：Had
✅ 正解根拠:仮定法過去完了 If S had p.p. の倒置形。If を省略して Had を文頭に置く。
🎯 秒解きポイント:文頭に Had / Were / Should があり主節に would have / would があれば仮定法の倒置。