_______ caused the accident is still a complete mystery.
| A．What | B．That | C．How | D．Where |
When I went to their house, there was no light on. They _____ at home.
| A．can’t be | B．couldn’t be |
| C．can’t have been | D．mustn’t have been |
In many countries in the world, breakfast is a snack _____ a meal, but the traditional English breakfast is a full meal.
| A．other than | B．more than | C．rather than | D．less than |
I asked her _____ have to study before I could go to university.
| A．how long would I | B．how soon would I |
| C．how long I would | D．how soon I would |
_____ surprised me most was to see so many people waiting for my arrival.
| A．That | B．It | C．Which | D．What |
--- Why did you call the police?
--- I got home and found my house _____.
| A．broken up | B．broken down | C．broken in | D．broken out |