过去分词和现在分词完成被动式的区别

过去分词和现在分词完成被动式的区别：
　　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。