Because he had not received a reply ,he decided to write again.
这是复合句,改成简单句,就要用分词结构.
having received 分词的否定,就是直接前面加not ,
即:B的形式.Because he had not received a reply ,he decided to write again.这里的 received是什么成分？谁是谓语？Because he had not received a reply ,he decided to write again.这是复合句, 不是简单句;因为他还没有收到答复，他决定再写信。Because he had not received a reply 这个分句,变成简单句的时候, 过去完成时态的谓语动词,就改成了分词形式.也就是说Because he had not received a reply谓语动词 received是过去完成时态，变成not having received a reply这个简单句时，having received是过去分词，那having received是不是过去分词的完成时态呢？书上写过去分词没有时态之分啊having received, 是(过去)完成时had received 的分词形式.过去分词本身自然没有时态之分彻底蒙了，我再想想看，谢谢你这个语法点是比较难的,不要着急,找本书,或在网上搜下,系统看几遍就好了.