One solution to this problem now is sustainable development.
| A．discussed | B．discussing |
| C．to be discussed | D．being discussed |
Ladies and gentlemen, please fasten your seat belt. The plane _____ .
| A．takes off | B．is taking off |
| C．has taken off | D．took off |
I was told that the singer ____ in 1980.
| A．was born | B．is born |
| C．had been born | D．had born |
--How much pepper did you put in the soup?
--I'm sorry to say, ____. I forget.
| A．no one | B．none |
| C．nothing | D．no |
The story is about an old Indian villager and an American tourist in India, _______ understanding the other’s language.
| A．none of whom | B．both of them |
| C．neither of them | D．neither of whom |
The doctor suggested ____ sent to the hospital.
| A．you to be | B．that you be |
| C．that you was | D．that you are |