過去分詞作狀語問題Having been suffered such heavy pollutin already,it

題目：

過去分詞作狀語問題
Having been suffered such heavy pollutin already,it may now be too late to clean up the river.
Having been told many times ,he still couldn't understand.
爲什麼第一句要去掉been 第二句不用?

解答：

第一句是主動語態,主語是河,經受了如此嚴重的汙染,現在治理這條河流太晚了
第二句是被動語態,雖然被講解了很多次,他還是不懂