3 . Wearing a protective suit, Jiang Aiqin waited for the arrival of the garbage trucks.

She was about to start her voluntary work: garbage classification. But once she’d been working for a while, the 17-year-old of Chongqing Nankai Middle School realized that sorting out garbage by hand is a torturous(折磨人的) and time-consuming process.

From the 2,000 replies to an online questionnaire she designed, Jiang found that only half of the residents were able to sort out their garbage and many blamed their difficulties on the poor classification system.

Jiang wondered what she could do to help out with the problem. It was her mother that gave her the hint: She suggested that Jiang introduce artificial intelligence(人工智能) into garbage classification.

Inspiration struck, leading her to design a new app.

When users come to the front of a bin, they describe the garbage on their smartphones and create a QR code sticker(二维码标签). Using a machine beside the dustbin, they scan the code, which then tells them the correct bin to use.

With the app, you can track(追踪) the progress of your trash. “It would save residents troubles and inform them about garbage classification,” said Jiang. “As the method spread from household to household, the efficient disposal of garbage in cities would be established.”

Although the teenager had a blueprint in mind, she didn’t know how to program an app. To this end, Jiang visited an environmental protection company for help. She told the company about her app idea, and as a result won recognition for her innovation(发明) from the company’s experts.

Finally, Jiang did a further duty as a citizen: She wrote to local government about her idea. Replying, the government told her that “The design is creative and workable” and that “a clean environment needs the help of citizens like you.”

Every day people throw away a lot of household garbage – paper, cans, kitchen waste, used batteries and glass     1     sorting it.   There are many problems     2    (cause) by unsorted garbage. On one hand, it's     3    great waste of resources. On the other hand, the disposal of unsorted garbage can cause serious environmental pollution,     4    does harm to people's health. Now our government has realized the importance of garbage sorting. So far many activities     5     (hold) to teach people how to sort garbage     6     (proper).

People in cities, like Beijing and Shanghai, are required to sort garbage into four categories - kitchen waste, dangerous waste,     7     (recycle) waste and other waste. Also, they can get certain points for sorting their garbage. When they accumulate enough points, they can go to the community     8     (exchange) them for some gifts of daily use. However, still a lot of people in China lack the     9     (aware) of garbage sorting. Changing people's mindsets and habits will take a long time. But once one person       10     (develop) the habit of garbage sorting, more may be influenced to do the same.