Many countries have improved their sanitation with improved standards of waste disposal.
第一個improved前有with ,還能看作完成時嗎?還是被動的隨著或者形容詞?
have improved：目前完成時，謂語。主動意義。
improved standards of waste disposal. 過去分詞作定語，被動意義，修飾standards。沒必要區別improved是形容詞還是過去分詞，就按過去分詞對待。