1. Although a country is divided, mountains and rivers last forever, and the spring of trees and grass is back. Sad state, can not help but burst into tears, amazing birds, leaving sorrow and hate. The war lasted for more than half a year, and letters from home were rare, with a hundred thousand gold. Twisting with melancholy, scratching my head and thinking, the more I scratch my white hair, I can hardly insert a hairpin.
2. Two orioles sing green willows, and a row of egrets go up to the sky. My window framed the snow-covered western hills. My door often says "goodbye" to ships sailing eastward.
There are no birds in a hundred mountains, and there are no footprints in a thousand paths. A boat on the river, a fisherman wearing his webworm moth; Fishing alone is not afraid of snow and ice.
Knowledge expansion: introduction to birds
1. Definition
Birds are a kind of vertebrates, belonging to the class Ornithoptera, which have the characteristics of feathers, spawning and flying. In the process of evolution, birds have formed unique characteristics such as bone structure, respiratory system and feathers that adapt to flight.
2. Features
Including feathers, beaks, wings, spawning and thermal stability. Feather is the most striking feature of birds. It not only has the functions of heat preservation and flight, but also plays the role of color, display and protection. Beak is a specialized structure of bird's mouth, which has different shapes and adapts to different food feeding methods. Wings are the main organs for birds to fly. They can fly by vibrating and adjusting the posture of wings.
classify
Birds can be divided into different orders, families, genera and species according to their morphology and ecological habits. At present, there are about 10000 species of birds, including passeriformes, pigeons, parrots, ducks and so on. There are also specific families, genera and species under each project, forming a rich and diverse bird population.
4. Living habits
The living habits of birds vary from species to species. Some birds live on land, some live in water and some fly in the air. Birds have different feeding habits, including carnivorous birds, herbivorous birds and omnivorous birds. Birds will build nests, lay eggs and hatch young birds during the breeding season, and some birds will migrate to find suitable habitats and food resources.
5. Ecological function
Birds play an important role in the ecosystem. They participate in the transmission and energy flow of the food chain, control the pest population, spread pollen and seeds, and promote the reproduction and renewal of vegetation. At the same time, birds are also a part of beautiful biodiversity, which is protected and appreciated by people.