The box was so heavy that I couldn't lift it .中为什么用couldn't 而不用ca_英语解答

The box was so heavy that I couldn't lift it .中为什么用couldn't 而不用can't

人气：391 ℃　时间：2019-11-06 15:25:32

解答

时态要保持一致,前面用是的was,所以这里用couldn't.