现在分词的完成时的被动语态做状语

Having written an important letter ,I listened to the music for a while .
写完一封重要的信后,我听了一会音乐.
Having finished the experiment ,he left the lab .他做完试验离开了实验室.
Not having received an answer ,I decided to write another letter to him .
由于没收到回信,我决定再给他写封信.