Every possible means ______, but none proves successful.
| A．has tried | B．have been tried |
| C．is being tried | D．has been tried |
Williams sisters completed their high school_______ developing their tennis careers.
| A．as | B．until |
| C．when | D．while |
---Did you see a man in black pass by just now?
---No, sir. I _______ a newspaper.
| A．read | B．was reading |
| C．would read | D．am reading |
Hurry up, _______ you will miss the bus.
| A．otherwise | B．however |
| C．and | D．so |
Attention, please！The plane to London_______ off at 9: 00.
| A．took | B．takes |
| C．was taking | D．has taken |
Every minute of the day is filled _______ urgent matters.
| A．about | B．of | C．with | D．for |