题目内容：

    Have you noticed the waste bins(垃圾桶) in different colors on the street? Do you often put all the waste in the same bin? It's reported by Changchun Daily that people must do waste sorting(分类)in most places in Changchun at the end of 2019. Waste sorting is a wonderful way to make good use of energy and protect the environment. But do you know how to sort the waste?

Usually, people should sort their waste into four groups: wet, recyclable, harmful and dry.Different kinds of waste should go into different bins. Wet waste means the things you don't want but pigs can eat, mostly coming from your kitchen. Things that can be used again, such as paper, metal and glass, are recyclable waste. Harmful waste might be dangerous or cause serious pollution, like medicine and batteries(电池). And any waste that's not wet, recyclable or harmful will go into the dry waste bin.

Different countries are trying different methods to sort the waste. A university in England has invented a smart bin. When people drop their waste into the bin. It can tell what kind of waste it it and sort it correctly. The bin can also compress the waste to make it smaller in size and take up less space. In South Korea, people have to separate their food waste from other kinds of waste and pay for it. The more food waste they throw away, the more they pay. Japan has the strictest rules for waste sorting in the world. For example, plastic bottles and their caps should go into different bins.

根据短文内容，选择最佳答案。

1.When must people do waste sorting in most places in Changchun?

A.At the end of 2019. B.At the end of 2018

C.At the beginning of 2019. D.At the beginning of 2018.

2.According to the second part, how many groups should people sort their waste into?

A.Five. B.Four. C.Three. D.Two.

3.Which of the following should go into the harmful waste bin?

A.Glass. B.Metal. C.Paper. D.Medicine.

4.What does the underlined word "compress" in the third part probably mean?

A.扩展 B.延缓 C.压缩 D.膨胀

5.What can you learn from the passage?

A.Changchun has the strictest rules for waste sorting in the world

B.All the countries around the world are doing waste sorting these days.

C.Waste sorting can help make the earth a better place for people to live in.

D.People in South Korea have to pay for the harmful waste they throw away.