great changes have taken place in the past ten years.为什么不用被动

great changes have taken place in the past ten years in chin great changes have taken place over the past fifty years. In the past (a few;few)years,great changes have taken place great changes have taken place in the village ____the years 填词 In past 20years,great changes have taken place in China e Great changes have taken place in Shanghai in the past few y Great changes have taken place in my hometown in the past fe Great changes have taken place in biejing for the past few y 英语改被动Great changes have taken place in the city and we have Great changes have taken place___.A in the past thirty years great()have taken place in my home town in the past ten year Great changes( )place in China in the past 20 years.