If we don’t take some measures to protect this kind of plant, it will ____ soon.
| A．die out | B．die down | C．die from | D．die of |
This is a simple idea, but that is hard to put into practice.
| A．one | B．it | C．that | D．those |
– Who is the man standing there?
– If you know, his name is Mike.
| A．must | B．can | C．may | D．would |
One solution to this problem now is sustainable development.
| A．discussed | B．discussing |
| C．to be discussed | D．being discussed |
Wind power units are placed ______ there is a lot of wind.
| A．where | B．when | C．which | D．that |
Recently, there a boom in population movements.
| A．is | B．was | C．has been | D．had been |