247 graduate students of Fudan University have volunteered to teach the children in Xihaigu region（地区）of Ningxia for the past 22 years. The region used to be poor because of its terrible natural environment. "We expect to make a difference to the children's life by sharing our knowledge in different fields, " one of the volunteers says.

The students have different abilities, so the volunteers have used different teaching methods to help them develop good study habits. "Local children had never learned English before, so we started with basic knowledge like English letters and pronunciation, " says Li Lianshuo, a Fudan volunteer. The volunteers help the students remember English words, read articles and deal with their study problems.

"We visit the students' homes in our free time. We communicate with their parents so that we help the parents understand the importance of children's education, because the parents didn't care much about it years ago, " explains Yang Chenhaotong, who was the leader of the volunteer team in 2019. According to Yang, the parents give their children a lot of support in their studies now.

The volunteers have helped the local children with their studies. They have also set up football clubs and held many ball games to make the children's life colorful. Fudan University has also given away more than 10 million yuan to the region to build playgrounds（操场）and other buildings over the past 22 years.

"Thanks to my volunteer teacher, my life has changed a lot. I will study hard and become an excellent person like her, " Li Sumei, a local student, says excitedly.

Wetlands are any land that is flooded with shallow water all or most of the time. They are a natural water holding system.

There are many types of wetlands. Among them, bogs, marshes and swamps are the three main types. The different types of wetlands have different kinds of plants. Only mosses（苔藓）and a few other kinds of plants can grow in bogs Grassy plants like cattails（香蒲）and reeds（芦苇） are the most common plants in a marsh. A swamp is a forest whose ground is underwater all or most of the time. Unlike bogs or marshes, a swamp is full of trees and bushes. It's not a good idea to go exploring a swamp without a guide. There are hidden pools of water, thick mud, and sometimes big crocodiles （鳄鱼）looking for their next meal.

Hungry crocodiles aren't the only animals that make the wetlands their home. Otters, turtles, frogs, snakes and many other animals do too. The water is home to many kinds of fish and crabs. Birds, including ducks, geese and cranes, use wetlands seasonally during their long migrations.

Wetlands are important because they provide habitats for plants and animals. A wetland system can also protect shorelines, make polluted waters clean, prevent floods, and restore underground water supplies.

According to WWF, more than half of the world's wetlands have disappeared since the beginning of the 20th century. If this continues, countless plant and animal species will surely die out. Without wetlands, cities have to spend more money to treat water. Don't feel helpless. Try to do your part to protect them right now. Here are some ideas.

The Beijing 2022 Winter Olympics has already come to an end, and Chinese athletes (运动员) have made great achievements. But how will the stadiums (场馆) be used after the Olympics?

The designers have already considered that question in their designs (设计). The plan is to let the stadiums serve common people and increase their interest in winter sports. Just as one of the designers of the Beijing 2022 Winter Olympics said, " The stadiums can not only serve professional athletes in the games, but also serve the public after the games. "

For example, the professional ice race lanes (车道) for athletes are 121 meters high and are not fit for amateurs. So the National Ski and Sleigh Center has kept a special lane for common sport-lovers. The height of the lane is about 40 meters. This can make sure they will stay safe.

The National Ski Jumping Center in Zhangjiakou, Hebei Province will continue being open to the public for skiing in winter and jogging in summer. In fact, people can make use of the stadiums all year round. On the top of the center, people can walk and enjoy the beautiful scenery. There is also a standard football field that can hold 6, 000 people. Even concerts and cultural fairs can be held there as well.

Time will tell whether the stadiums can be really made good use of after, the Olympic Games. In China, 300 million people have already taken part in ice and snow sports because of the Beijing 2022 Winter Olympics. Hopefully, that number will continue to rise with plans like these. After all, snow and ice sports belong not only to talented professional athletes, but also to everyone interested in them.