----- The windows must have taken you quite a long time that day.
----- Right. They ______ for months.
| A．haven’t been cleaned | B．didn’t clean | C．hadn’t been cleaned | D．haven’t cleaned |
If the dog hadn't woken us, we wouldn't have noticed the fire and it __________ to the house next door.
| A．could spread |
| B．should have spread |
| C．would spread |
| D．might have spread |
As civilization __________，more and more people have realized the importance of preserving rare animals from dying out.
| A．stretches |
| B．spreads |
| C．extends |
| D．expands |
Was it __________ the inter-national conference that made the city the focus of this area?
| A．held |
| B．hold |
| C．holding |
| D．being held |
-Why are you so late?
-We were __________ by the terrible traffic.
| A．set up |
| B．put up |
| C．brought up |
| D．held up |
With more people __________ the traffic rules, our city is becoming better organized.
| A．respect |
| B．being respected |
| C．respected |
| D．respecting |