A.accordance
B.aged
C.bad
D.bankrupt
E.comparison
F.decline
G.decreased
H.dramatic
I.good
J.regularly
K.repeated
L.rocketing
M.shrinking
N.successful
O.suddenly
参考答案K
解析:
【解析】K.repeated。分析句子结构,主语是he,后面是the exercise,很明显缺少谓语动词,再看时间是last year,所以本空应填一个过去式形式的动词.he是人称代词,指代Smith。本段第l句说back in 1990,Smith conducted interviews,本句话说last year he 35 the exercise,questioning 2300 pupils,可见他是又一次组织了这个活动,故答案为K.repeated(重复)