Although we have been working in the same office for several ages, she me much impression.
| A．hasn’t left | B．didn’t leave | C．doesn’t leave | D．isn’t leaving |
—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 |
After studying mass of data，they drew a conclusion
________China is still a developing country.
| A．that | B．which | C．／ | D．where |
Along with the letter was his promisehe would visit me the New Year.
| A．which | B．that | C．what | D．whether |