up the river.

　　这条河遭受了如此沉重的污染，现在要治理可能为时已晚。

　　(2)分词的逻辑主语要和句子的主语一致。

　　Having been trapped in traffic, he was late for work.

　　因为交通拥挤，他上班迟到了。

　　(3)分词的否定形式是在分词前加"not"。

　　Not having received his reply, I rang him up again.

　　没有收到他的回信，我又给他打了电话。