根据句意和汉语注释，写出单词的正确形式。
When the doctor came, the victim has already stopped _______ (呼吸).
_______ (立即), the enemy disappeared on the early foggy morning.
It's not surprising to see so many _______ (推销员) in such a big electrical shop in China.
As we know, air _______ (污染) might cause many serious diseases.
