为什么有have taken place 这种被动用法?

为什么有have taken place 这种被动用法? 英语改被动Great changes have taken place in the city and we have taken为什么被动  现在完成被动时Great changes have taken place in my hometown and a l have been taken place 与have taken place的区别 be taken place 无被动语态? Great changes have taken place there. Many changes have taken place since Great changes have taken place there Great changes have taken place since liberation Great changes have taken place ...in china Great changes have taken place in China.