—It was a red light, William. You ____ the car.
—Sorry. I didn’t see it.
| A．must stop |
| B．should stop |
| C．must have stopped |
| D．should have stopped |
While he was investigating ways to improve the telescope, Newton made __ discovery which completely changed __ man’s understanding of color.
| A．a, / | B．a, the | C．/, the | D．the, a |
The most important thing about cotton in history is __ part that it played in __ Industrial Revolution.
| A．/, / | B．the, / | C．the, the | D．a, the |
When he left __ college, he got a job as __ reporter in a newspaper office.
| A．/, a | B．/, the | C．a, the | D．the, the |
__ on-going division between English-speaking Canadians and French-speaking Canadians is __ major concern of the country.
| A．The, / | B．The, a | C．An, the | D．An, / |
If you buy more than ten, they will knock 20 pence off __.
| A．a price | B．price | C．the price | D．prices |