根据短文和图表内容,选择最佳答案。The temperature has dropped to 30 degrees below zero. But that doesn't stop the fishermen of Songyuan City in Jilin Province. Each morning, they get up early and rush to Chagan Lake with a group of horses. The fishermen use the horses to help pull fishing nets out of the frozen (结冰的) lake.
For centuries, those living around Chagan Lake have kept alive the tradition of ice fishing. They dig holes through the thick ice and use a huge net to catch winter fish in the freezing water. This special method has been listed as an intangible cultural heritage (非物质文化遗产).
Every year in December, there is a winter fishing festival, which marks the beginning of the winter fishing season. Over 20 activities are held during the festival, such as winter sports competitions, nature watching, and the selling of the first-caught fish.
None of the tourists at this year's festival would ever imagine that Chagan Lake used to be only tens of square kilometers in size. In the past, there was little rainfall and the lake grew smaller over time. Also, overfishing is one of the main reasons.
To bring Chagan Lake's beauty back, the government used a lot of different methods. They brought in water from the Songhua River, grew more plants, and kept the water clean. The lake now covers about 500 square kilometers, and fish numbers have returned to a normal level. Now, an increasing number of tourists flock to the lake each year to experience the ancient ice-fishing tradition.
The special event of ice fishing at Chagan Lake is sure to continue into the future. It's a hit with tourists, and the locals say that the life of Chagan Lake will only get better and better.