The most impressive sight in China，one of the wonders of the world，_____ the Great Wall.
A.is B.are C.was D.were
The factory used 65 percent of the raw materials,the rest of which saved for other purposes.
A.is B.are C.was D.were
—Why does the lake smell terrible?
—Because large quantities of water_______________.
A.have polluted B.is being polluted
C.has been polluted D.have been polluted
One-third of the country____covered with trees and the majority of the citizens_______black people.
A is；are B is；is C.are；are D.are；is
Was it not until you began to work —— how much time you had wasted?
A.did you realize B.that you realized C.did you not realize D.that you didn’t realize
Peter has gone to Beijing, but I’m wondering why he ________ in such a hurry.
A. left B. has left C. leaves D. was leaving
