My sister many items when she moved into a new house.

Noise pollution is a serious problem in big cities. A scientific study found that Guangzhou had the worst noise pollution, followed by Delhi in India and Cairo in Egypt. Beijing came sixth. To help track(跟踪) and! control noise pollution, a noise map has been developed by the Shanghai Academy of Environmental Sciences. It allows people to "see" noise.

On the map, there are a total of 12 colors which stand for 12 noise levels. For example, purple means noise between 30 and 35 decibels(分贝) while dark green means noise between 40 and 45 decibels. The area where the noise is between 60 and 65 decibels is showed in bright red. Blue means noise between 75 and 80 decibels. Roads along busy elevated ways(高架道路) are often red or blue, while neighborhoods and parks are usually quieter, showing a color of green or purple.

The noise map is not a new invention. European Union member countries have been required by the EU to make noise maps for cities with a population of over 250, 000. Some cities in Japan, South Korea and the US also have noise maps. Most of these countries don't update their maps often, but the noise map of Shanghai gets updated every 20 minutes, giving researchers an idea of how the noise level changes with time in certain areas. For example, noise levels may rise as a car comes near, and fall again after it has passed. Weather and season also affect noise levels.

The noise map will be used to help reduce noise in cities. It can also be helpful if you're looking for a quiet neighborhood to live in.

When people think of tigers, they think: strong and dangerous. But now, the big animal is calling for our help.

There were once eight kinds of tigers in the world, but three died out during last century. In the last 70 years, the number of Siberian tigers(东北虎) has gone from as many as 300 to somewhere between 18 and 22.

The World Wildlife Fund (WWF) started a program recently. It is about to put an end to tiger poaching(非法狩猎) and save wild tigers. China, together with 12 other countries, has joined in. The aim is to double the number of wild tigers in the next ten years.

According to the research by Chinese officers and the WWF, the Siberian tiger is already one of the world's most endangered animals. "If the government doesn't take any action，it's quite possible that there will be no more Siberian tigers in China in 10 to 20 years, " said Zhu Chunquan, director at the WWF"s Beijing office.

Wild animals such as the red deer, sika deer(梅花鹿) and wild boar (野猪) are the tigers' main food. The poaching of these animals is the greatest threat to tigers. Traps(陷阱) are also a threat. In October, the people of Mishan, Heilongjiang found a dead Siberian liger with a wire(金属丝) around its neck.

"Volunteers from the WWF remove traps every year, but the fact is that we cannot clear all the traps by ourselves," Zhu said. The most important thing people can do is to save the animals which tigers eat. "To protect the tigers, we need to call on more people to stop eating wild animals. "

Humans share the earth with many different kinds of wildlife. According to a UN report, 1 million of the earth's 8 million species (物种) are in great danger. According to the report, the world's population has more than doubled (from3. 7 to 7. 6 billion) in the last 50 years. Humans have used more than a third of the world's land and 75% of fresh water to grow crops and raise animals. As a result, there is less available land and water.

Because of human activities, more and more species are at risk of extinction(灭绝). This could have serious influences on the earth. The scientists also believe that there could be a sixth mass extinction, the first to be caused by humans.

The last one happened 65 million years ago, and that time the dinosaurs died out.

"It is clear: The future will be bad for us if we don't act now. There is no future for us without nature," said Sandra Diaz, one writer of the report.

For example, the use of tiger bones and the ivory trade are not allowed in China now.

There are things that we can do personally to save species. For example, don't buy products made from wildlife and stop wasting water.

All the lights must be when you leave the room.

While most 11-year-olds use their pocket money to buy the latest toys or their favorite snacks, Joslyn Stamp uses it to protect the environment. She has joined the ColorCycle program and helped keep thousands of used and dried-up markers(记号笔) from ending up in landfills(垃圾填埋地).

At first, Stamp found there were lots of used markers in the bins of her school but the school didn't have a good way to recycle them. She wanted to do something. So she searched online. She became excited when she learned that the company Crayola started its ColorCycle program, which could deal with the problem.

What Stamp needs to do is collect and send the used plastic markers to Crayola. Then Crayola will turn them into energy that can power cars and homes.

Stamp joined the program and began her recycling project at her school in October 2017. She didn't expect that so many students took an interest in her project. To her surprise, 100 markers were collected with the help of other students on the first day. Then she bought some bins with her pocket money and put them at four schools, a daycare and two libraries. Now she picks up markers from these bins at least once a month. She has recycled more than 10, 500 markers since then. That's about 211 pounds.

"Anyone can make a difference. You just have to start somewhere, said Stamp. " If we each help a little, we can save the earth. "

Many volunteers are an active in making Yantai a civilized city.

I live in Missouri, near a river called the Jacks Fork. Before I was born, my grandparents decided to help keep the1clean. So they started a club called Stream Team 713. I like its another2better--the Jacks Fork River Rats! Our club makes sure the water is clean and healthy for fish and people. And now I'm big enough to help 3 the river too.

Picking up rubbish is4 a treasure hunt(搜寻). My friends and I find plastic bags, bottles, paper, and all kinds of things. There used to be even more rubbish here. On one weekend, my grandparents5 picked up 6 tons of rubbish. That's as much as the weight of an elephant!

That rubbish was 6 to the river or the animals and plants that lived there. So the River Rats taught people who were playing around the river to take rubbish with them rather than 7 it. Now there's much less rubbish for8to pick up. Maybe one day we won't find any rubbish here.

My favorite job is to look for water bugs(虫子)! The bugs like to stay at the river bottom. Some bugs don't9how dirty the water is, but other bugs can only live in clean water.

10we find lots of bugs that need clean water, then we will know the river is clean enough for fish and for us.

I love taking care of the Jacks Fork River. We help make sure it's a clean, safe place for me and my friends to play.