— Are you a teacher?
— No, but I ________ in Quanzhou No. 3 High School for 3 years.
| A．taught | B．has taught |
| C．teach | D．had taught |
– 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 |
______developing countries need to do is to stop poverty.
| A．How | B．That | C．Which | D．What |