1. What kind of bird is a swan? Swan, a kind of bird, belongs to a kind of bird and is widely distributed all over the world. Swan is the largest kind of duck. Its neck is very long and thin, as long as its body. Swan likes to inhabit some lakes and swamps. Aquatic plants in the water are their main food. They also eat some birds, such as mollusks and snails and swans. They are monogamous all their lives, and they will be together all their lives. They only breed once a year, and swan eggs are nearly 400 grams. Every year, they have the habit of migrating in groups of three or five.

2. 18 Why did the wintering swan fly back to Sanmenxia for the winter? Because swans themselves are migratory birds, they fly from the south to the north in groups in March and April every year to lay eggs and breed in the north. After1October, they will migrate to the south in groups, and they often find some warmer places to spend the cold winter, so swans choose Sanmenxia area with spicy climate and warmer winter climate for winter, because the temperature in Sanmenxia area is relatively suitable for swans' life and the environment is very beautiful.

3. What is the environment like in Sanmenxia area? Is it suitable for these swans? Sanmenxia area is located at the junction of Shaanxi, Henan and Shanxi provinces. There are many wetlands and lakes nearby, and the younger brother in Sanmenxia reservoir area is already a national wetland nature reserve. The state has carried out some protection actions for swans in this area, and the improvement of the water quality of the Yellow River has attracted many swans to come here. Every winter, the relevant departments will manually put in some foods that swans like to eat, so Sanmenxia area is very suitable for swans to spend the winter.