_______ such heavy pollution already , the river is no longer what it used to be .And the City Council concludes that it may now be too late to clean it up .
A.Having sufferedB.SufferingC.To sufferD.Suffered在线课程A
测试语言点 ：动词的现在分词作为状语，表达因果关系的不同层次。
要吸取的经验 ：
要依据上下文选词填空。上文： such heavy pollution already ,遭受如此严重污染 ，下文 ： it may now be too late to clean up the river .结果清理河道为时已晚。不过，这里是下文决定上文；既然清理河道为时已晚，那么其原因必然是“已经”严重污染到不可挽回的地步了。所以，选B． Suffering表示现在正在受到污染，其层次不够，C． To suffer表示目的，D． Suffered仅仅可作谓语，都不对。
※ 此题有语病。按照“托福考试”（TOEFL）要求，应视为“修饰语不合逻辑”（Illogical modifiers）。
下面的一对句子选在自1979年的“BARRON扴 HOW TO PREPARE FOR THETOEFL”一书（p.80）：
Incorrect: Having been delayed by heavy traffic, it was not possible for her to arrive on time.
Correct: Having been delayed by heavy traffic, she arrived late.
这个句子是1994年1月“托福考试”第32题，与上述错误相似。Judging to be the best boxer of his time , Sugar Ray Robinson lost only 3 out of 137 fights.
ABCD
※※此题的正确命题似乎应该是这样：
_______ such heavy pollution already , the river is no longer what it used to be .
And the City Council concludes that it may now be too late to clean it up .
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A． Having suffered B． SufferingC． To sufferD． Suffered
※※※关于此题“有语病”的看法，2004年在上海卷（42）中，再次得到验证：
42. Having been attacked by terrorists, ________
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A． doctors came to their rescue.B． the fall building collapseD．
C． an emergency measure was taken.D． warnings were given to tourists. Key: B