Unit3 Fairness For All
解析：ever since也是現在完成時態的標志。故選c。
22. she ______ her hairstyle in her hometown before she came to chongqing for a better job. (重慶)
a. would change b. has changed c. changed d. was changing
解析：該題中change發生在came前。但是沒有過去完成時態had changed供選擇，故只有選c。語法規定：當不強調某一動作發生在過去某動作之前、或讀者一讀到就明白哪個動作發生在前，可以用一般過去時態代替過去完成時態。
23. sales of cds have greatly increased since the early 1990s, when people _____ to enjoy the advantages of this new technology. (江蘇)
a. begin b. began c. have begun d. had begun
解析：時間狀語從句描述的還是過去的事實。故選b。
24. it is said in the book that thomas edison (1847—1931) _____ the world leading inventor for sixty years. (遼寧)
a. would be b. has been c. had been d. was
解析：表示過去的狀態。故選d。
25. he kept looking at her, wondering whether he ______ her somewhere. (湖北)
a. saw b. has been c. sees d. had seen
解析：see應該發生在kept looking之前。故選d。
26. –george and lucy got married last week. did you go to their wedding? (湖北)
–no, i ________. did they have a big wedding?
a. was not invited b. have not been invited c. hadn’t been invited d. didn’t invite
解析：在did go to their wedding之前沒有得到邀請。故選c。
27. —i hear jane has gone to the holy island for her holiday. (湖南)
—oh, how nice! do you know when she______?
a. was leaving b. had left c. has left d. left