阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号

中词语的正确形式填空，并将答案填写在标号为1－5的相应位置上。

    In the past, the people in Zhanjiang lived a poor life. The houses were old and small. 1______ (pollute) was

very serious, and there was rubbish everywhere. The traffic was not convenient, so few visitors came here.

    Now great changes have 2______ (take) place in Zhanjiang. The environment has become more beautiful.

The rivers have turned 3______ (clear) and the sky has turned bluer. There are trees, flowers and grass

everywhere. People live a better 4______. There are many large and bright buildings. Many people have their

own cars. Every year, thousands 5______ people from all over the country come to our city.

    We're sure Zhanjiang will become better and better in the future.