22. —Mr. Smith _____ in Russia for 10 years. —No wonder he can speak Russian fluently and now teaches Russian in a Chinese college. had stayed B. has stayed C. stayed D. stays
Now I need some time to my thoughts thoroughly, because I want to give them a perfect report. After all, it is the first time that I have visited this school and given a lecture to the students.
According to the data, China supplies more than 90 percent of the world’s rare earth metals, but its reserves only about one third of the world’s total.