THOUGH特別用法

Though當連接詞，後面必須要接完整的句子，也就是要有主詞和動詞
這邊的the nation's four decades of extraordinary economy success只是名詞短與，(全部都是名詞，你找不到動詞)，所以並非句子，也就沒有辦法使用though了。

所以這邊如果你要用though的話
句子可能就必須要改寫成
It is showed that both the public and the government agencies had realized that though the nation has achieved extraordinary economy success during the past four decades, serious damage was being done to its natural resources.

希望這樣夠清楚

2014-01-01 18:34:30 補充：
又如：

Despite his success and wealth, he sometimes feels extremely lonely.
儘管他很成功，很富有，他有時候還是感到很孤單。

或是
Though he is a successful and wealthy person, he sometimes feels lonely.

2014-01-01 23:15:16 補充：
你說的if省略主詞的情況能否給個例句?

2014-01-01 23:20:24 補充：
根據我手邊的資料應該是可以
如：Though (he was) driving slowly, he couldn't stop in time to avoid the accident.

參考資料：http://www.englishforums.com/English/DespiteVingThoughVing/xznb/post.htm

though 是連接詞所以可以分詞構句方式使用
Though being ill,he insisted on going to school.

though是從屬連接詞，只能接子句。despite是介系詞，可以接一名詞片語當受詞。