根据句意和汉语注释，在空格内写出单词的正确形式
There is more  ______ (污染) in our city now than before.
The Summer Palace is a beautiful and ________ (安静的) place.
Now many new teachers go to teach children in the _______ (西北方) of China.
It is polite of us to give our seats to       （患病的）people on the bus.
When we go on a school trip, we’d better wear _______ (舒适的)clothes.