within five years,more colour than black-and-white TV sets were being used这是课本中原句,为什么用were being used?详细说明理由

Within five years 怎么个用法? within用法可以加钱吗?within five dollars Five Long Years 歌词 in five years' time Five years ago for five years 中文 Five years meter These five years of 英语翻译Can you to 　　a　　horse　　within　　five　minutes．　　His cousin could swim when she was four years old　意思相同的句子 within five years,more colour than black-and-white TV sets were being used这是课本中原句,为什么用were being used?详细说明理由 can i get there ( ) ( )within five minutes in和within的区别Scientists say Parkin's new computer memory could begin to replace flash memory (in) three to five years括号的in可以用within替换吗,为什么 seven years within an hour 怎么翻译? five years before 用法和five years ago的区别 Five years has past还是Five years have past? We have lived in this city _____A five years agoB for five years agoC since five years agoD five years A Roadmap for Five Years Rose is over five years