― _____ An accident has happened. A. Where was the accident? B. What happened? C. When was the accident? D. Why did it happen?
举一反三
- I happened __________ (be) there when the accident happened.
- When _____ the accident _____? A: A was; happen B: B did; happen C: C is; happen D: D was; happened
- I happened (wait) for the bus when the accident happened.
- Where was it ________ the road accident happened yesterday?
- Unfortunately, those who_____ the accident cannot recall what happened, Therefore the cause of the accident remains a mystery.