Zhalong is a nature reserve in Heilongjiang in north-east China. It is one of the world's most important wetlands. The reserve covers an area of 210,000 hectares. The area provides food and shelter for wildlife. It is an ideal home for different kinds of plants, fish and birds. Many birds live comfortably in Zhalong Nature Reserve all year round, while some only stay there for a short time. There are many fish in the wetlands, and the birds can easily catch them for food. Zhalong has long been called "the home of the crane". There are 15 crane species   in the world. 8 of them are in China and there are 6 species in Zhalong area. It is an important living area for the rare red-crowned cranes. There are not many red-crowned cranes in the world. Every spring and summer, red-crowned cranes lay and hatch   their eggs in Zhalong. Some people want to change the wetlands to make more space for farms and buildings. This means there will be less and less space for wildlife. More and more birds are in danger because they do not have enough living space. Many of them died. The Chinese government wants to protect these endangered birds, and they can be safe in Zhalong. Every year, a lot of tourists go to Zhalong to watch birds. This year, members of our Bird-watching Club are going to study the different kinds of birds in Zhalong and the changes in their numbers. The study begins next month. We  _  once a year. We are now inviting secondary school students to help. We need more people to help us count and do something to help the birds. Many people do not understand the importance of the wetlands. We hope this information will help them understand and make them actively take action to protect wildlife. The purpose of the article is to   _  .
attract more visitors to pay a visit to Zhalong Nature Reserve ask people to take action to protect wetlands and wildlife prevent people from watching birds in Zhalong Nature Reserve make people around the world know the Birdwatchting Club