it ( is )six years since he ( began )to learn english为什么是上面这个用法啊,since不是加完成时的吗,我觉得是was,began

Ann's brother is only six years old中对only six years old进行提问 It weights six tons.= __ __ is six tons.= It's six tons ____. he's been in Japan for six years.=it ___ six years ___ he came to Japan It’s six years since we knew each other同义句 we （） （） each other for six years. he's been 是什么的缩写在He's been learning English for six years and really loves it.是is还是has其他地方怎么区分 Is it a quarter to six? _______,it's a quarter _____ six.如题 Mary is six years old(对six years old提问 关于weigh的问题,It weighs six tons.= ___ ___ is six tons.= It's six tons __. Tom is six years old.Bill is twelve years old.（保持句意不变）Bill is ( )Tom’s ( ).` Tom is six years old.Bill is twelve years old(保持句子原意)Bill is _____ Tom's _____. 请问It is six years since I last met you 与 It has been six years since I last met you 有什么区别 It ___ six years since I left school.空格填什么?It ___ six years since I left school.能填is,那has been 能不能填啊? it's been six years这句话什么时态 been 的作用与时态 ‘It's been six years since we last saw each other’怎么翻译? it's been six years since we last saw each other是个什么从句? It's six years since we knew each other(改为同义句） He’s been learning English for six years and really loves it. Ann’s brother is only six years old.(就划线部分提问)（only six years old）有四个空然后是Ann‘s brother?