改错题He wrote a letter to his father last night,but I don't know wh_英语解答

改错题He wrote a letter to his father last night,but I don't know whether he has finished it
答案是将wrote改为was wirting.为什么呀

人气：486 ℃　时间：2019-08-21 18:10:57

解答

因为你不知道他写没写完,说明你看到的他的状态是进行时,正在写