34. ____ by the advances in technology, many farmers have set up wind farms on their lands.
| A．Being encouraged | B．Encouraging |
| C．Encouraged | D．Having encouraged |
—You seemed to be impressed by his skill.
—No. It was his courage ________ his skill that really impressed me.
| A．but also | B．except for | C．as well as | D．rather than |
—Who______ it be that is knocking at the door?
—It ______ be Father, but I’m not sure.
| A．can; must | B．can; may | C．must; can | D．may; must |
Once harm is _______ to the eco-system, all species will ________, including man himself.
| A．made; be in danger | B．done; be dangerous |
| C．caused; be endangered | D．done; be in danger |
The stamp on the letter is an art, from _______ we can get a lot of cultural knowledge.
| A．whom | B．which | C．them | D．those |
It is believed that a new kind of drug ______ by the scientists and they are hopeful that they will succeed in a few months.
| A．has been developed | B．is being developed |
| C．is developing | D．has developed |