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
______developing countries need to do is to stop poverty.
A. How B. That C. Which D. What
