The twins came to China three years ago.(改为现在完成时态的句子)

The twins have been in China for three years。The twins have been in China since three years ago。祝开心。 再问： 为什么不能把in改成to？ 再答： 不能改。 come to 是短暂性动词，和一段时间连用，必须转化为延续性动词 have/has been in 。。。。。。 可以把这作为规则记住。