一句话看不懂求解释
问题描述：
一句话看不懂求解释
Its author Richard Goldstone wrote in an American newspaper that his report would have been a different document had he known then what he did today.
这句话什么句式,最好分解下,断句,then是什么作用,是不是省略了if
答
Its …that是强调句 had he known是倒装句 then是连接词,“在什么之后”的意思