They sat face to face, ________ about the things they were interested in for a long time.
| A．and talk | B．talking | C．to talk | D．talked |
. We liked the oil painting better____________ we looked at it.
| A．as | B．while | C．the | D．the more |
If human beings had been a bit less greedy and cruel, more birds and animals dying out.
| A．ought to avoid | B．could have been avoided |
| C．should have avoided | D．might have avoided |
During the ten-day vacation, they traveled to France their own expense
| A．on | B．with | C．at | D．in |
We must keep our room clean. Dirt and disease go , you know.
| A．from time to time | B．hand in hand |
| C．step by step | D．one after another |
--Could I use your bike, Jack?
--Of course, you____________.
| A．can | B．may | C．could | D．might |