While he was investigating ways to improve the telescope, Newton made ________ discovery which completely changed ________ man’s understanding of color.
| A．a; 不填 | B．a; the | C．不填; the | D．the; a |
How can you expect him to make any progress ____ you never give him a chance to have a try?
| A．when | B．unless | C．even though | D．until |
---Is there any flight to New York?
--- I think there ______ be, for it is snowing so heavily.
| A．shouldn’t | B．mustn’t | C．can’t | D．needn’t |
---I have some good news for you. You’ve been accepted as a member of our club. ---_____________ That’s great!
| A．Good idea! | B．Pardon? | C．Congratulations! | D．Have I? |
Afer decades of effort, the city is still trying to_______ how to ban smoking in public places.
| A．look through | B．get through | C．figure out | D．take out |
________reasonable, the idea he________to create a friendly environment attracted much public attention.
| A．Sounded; came about | B．Sounded; came across |
| C．Sounding; came up with | D．Sounding; came along |