问题描述：
I will have written this letter.
改成被动语态是不是这样:This letter will has been written by me.原句的时态主要靠have 还是be来体现 即改被动后应该变成had 还是been
有什么规则吗
改成被动语态是不是这样:This letter will has been written by me.原句的时态主要靠have 还是be来体现 即改被动后应该变成had 还是been
有什么规则吗
问题解答：
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