In the past half-century, average ines quickly in developed countries, yet happiness levels have remained almost the same.
A. have risen
B. had risen
C. rose
D. rise
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(答案→)A. have risen
B. had risen
C. rose
D. rise
解析:考查时态。根据时间状语In the past half-century在过去的半个世纪,可知用现在完成时,选A。