来自唐立群的问题
BObhasbeencollectingkites__?Asince4yearsagoBsincehewastenyearsoldCfor4years
BObhasbeencollectingkites__?
Asince4yearsago
Bsincehewastenyearsold
Cfor4years


BObhasbeencollectingkites__?Asince4yearsagoBsincehewastenyearsoldCfor4years
BObhasbeencollectingkites__?
Asince4yearsago
Bsincehewastenyearsold
Cfor4years
C,有延续的意思,他这四年来一直收集着风筝