及物动词的过去分词没有完成式，但它有“完成”的含义，所以它可以代替现在分词完成被动式。
eg:The bridge had been weakened by successive storms and was no longer safe .=
Weakened by successive storms,the bridge was no longer safe.=
Having been weakened by successive storms,the bridge was no longer safe.=
这座桥接二连三地遭到暴风雨的袭击后，己经不安全了。
但若强调分词表示的行为发生在后一个动词表示的行为之前时，可用现在分词完成被动式。
eg:Having been warned about the bandits,he left his valuables at home。
当警告有强盗出没时，他就把贵重物品留在家里。
通常过去分词可作定语使用，而现在分词完成被动式却不能用作定语。
eg:The computer centre,opened last year,is very popular among the students in this school.(MET 93)
去年开办的计算机中心很受学生的欢迎。 (过去分词既能表示被动又有完成的含义)
The first textbooks written for teaching English as a foreign language came out in the 16th century.(NMET 94)
作为外语的英语教科书早在十六世纪就已经出版了。
Most of the artists invited to the party were from south America(MET 90)
应邀参加舞会的大多数艺术家都来自南美。下载本文
