_______, we would have prevented the catastrophe.
A: Had we known it earlier
B: If we knew it earlier
C: Did we know it earlier
D: Unless we had known it earlier
A: Had we known it earlier
B: If we knew it earlier
C: Did we know it earlier
D: Unless we had known it earlier
举一反三
- If we ______ earlier, we would not have missed the bus. A: left B: have left C: had left D: would have left
- If we had left a little earlier, we (catch)_________________the train.
- The project was completed earlier than we had expected.
- I felt as if we ______ each other for years. A: had known B: knew C: have known D: would have known
- If we had taken such effective measures much earlier, the river _____ so seriously now.