I am told that the new law will come into _____ on January 1st next year.

 --- How can I repair it? --- Well, look at the _________.

Once air pollution       in most cities, it is hard      .

_______ has been known that ______ other waste found in the ocean, the plastic  does not break down.

When we visited Zhou Zhuang again ten years later, we found it changed so much that we could hardly ________ it.