Nobody knows for sure how dinosaurs died out 65,000,000 years ago. It _______ because of sudden changes of their living conditions.
| A．must have happened | B．would have happened |
| C．should have happened | D．might have happened |
The most energetic and important festivals are ______ that look forward_____ the end of winter and to the coming of spring.
| A．ones; in | B．the ones; / | C．onesto | D．the ones; to |
At that time people would st
arve if food was difficult _______, especially during the cold winter months.
| A．finding | B．to find | C．found | D．to be found |
They took the injured straight to the nearest hospital. Otherwise some of them____________
| A．died | B．would die | C．might have died | D．could die |
____________you leave now, since here so much work has not been done yet?
| A．Shall | B．Must | C．Should | D．Can |
Rich as he is, he is not particular about____________he eats and drinks.
| A．which | B．what | C．that | D．these |