It's five years since___I came to this town等于it has been five years since i came to this town你写的2句有什么不同？it is 等于 has been ?还是's 是 has ?It's five years =it is five yearsit's been five years=it has been five yearsit is 不等于 has been谢谢你的回答 这个我也知道 但你的解释我不是很明白这句话答案是It's five years since I came to this town因为感觉since前面应该用have been而此句用it is 又是为何呢我说过这两句相等没有区别自从我来的这个城市，已经5年啦两种表达都可以这回明白了么