Why can birds fly in the sky, but we humans can't? 1. Because this bird is very light. 2. Use updraft. The powerful fish wings squeeze the air and make its body rise. First of all, there are thin and warm feathers outside the bird's body, which not only has the function of heat preservation, but also makes the bird's shape streamlined, which is conducive to flying. When flying, the wings keep flapping up and down, and the black beans drive the airflow, which will produce great downward pressure resistance and make the bird's body. Secondly, the bones of birds are thin and light, and they are hollow and full of air. By dissecting the bones of birds, we can also see that the skull of birds is a complete bone fragment, and the bones and vertebrae of different parts of the body are also healed together. There are hooked protrusions on the ribs, which hook each other to form a strong chest. This unique bird bone structure reduces the weight and strengthens the ability to support flight. Third, the pectoral muscles of birds are very developed and have a unique respiratory system, which is suitable for flying life. Birds' lungs are solid spongy, and there are also nine kinds of thin-walled gases. In the morning of flight, after the bird inhales air through its nostrils, part of it is used to exchange carbon and oxygen directly in the lungs, and the other part is stored in the air and then discharged through the lungs, so that the bird can inhale once during flight and the lungs can exchange gas twice. This is in addition, I think that in the bird's body, the structure of bones, digestion, excretion, reproduction and other organs tends to lose weight and enhance the flying ability, so that birds can overcome the gravity of the earth and fly very high. Birds' wings are the first condition for them to have flying skills. Under the same conditions with wings, some birds can fly very high, fast and far; Some birds can only hover, glide, or even fly at all. Visible, just wings, there is a lot of learning. The complexity of bird wing structure is no less than that of bird itself. If the feather structure of birds' wings can skillfully use aerodynamic principles, when they are fanned up and down or lifted up and down, they can use the principle of reaction to push the air forward; Feather structure is reasonable, which can effectively reduce the air resistance encountered in flight, and some can also eliminate vibration and noise. There are great differences in the wings of different kinds of birds, so that just the differences in wings have created many excellent and ordinary "pilots". Some national second-class protected animals, male weight 14 kg or more, body length 120 cm, wingspan 240 cm. For another example, the frigate bird with a wingspan of 2.3 meters usually flies in the coastal 160 km sea area and is a first-class protected animal in China. Can you fly only by wings? No, it is their special bones that send birds into the blue sky. Bird bone is an excellent "lightweight material", which is hollow and light. According to analysis, bird bones only account for 5% ~ 6% of bird weight; The human skeleton accounts for 18% of the body weight. Because the bones are light, the wings are very easy to drive, and there are many airbags connecting the lungs in the bird, which is very beneficial to lose weight and increase buoyancy. These superior conditions undoubtedly give birds the skills to fly and enable them to display their skills in another living space.
Adopt it
The idea that we humans can fly in the sky with dance is of great historical significance. You can buy an ultraman transformer.
Because we humans live on the ground, birds can fly in the sky, and humans can fly in the sky.
Kites fly in the sky. Kites fly happily in the sky with open arms.
Pigeons fly in the sky.
Personified sentences:
Lovely pigeons are flying freely in the sky.
Lovely pigeons are running freely in the sky.
Our seagull is flying in the sky. How to fill in the blanks? The vigorous seagulls are flying freely in the sky. Flocks of seagulls are playing and flying in the sky.
Clever seagulls soar in the sky against the wind and rain.
Strong seagulls are flying in the sky against the strong wind.
How to say 1 in Japanese for flying in the sky?
2. Flying in the air is the style.
Kites fly in the sky. The girl flying a kite is dancing in the sky.
"Why can't I fly in the sky? Like birds, "natural selection" means that the environment chooses creatures, and when they adapt, they live. If you don't adapt, you will be eliminated. In other words, creatures have different evolutions, and then nature chooses which evolutionary adaptation, and then he can survive. The direction of biological evolution is uncertain, and it won't be like what you said, because flying is good for people. It will develop in the direction of flying, and this process is quite long. With human physical condition, human weight and human physical condition, it is impossible for human beings to fly like birds, even if they have wings. The evolution direction of human beings is the continuous improvement of intelligence and the continuous decline of physical strength We can fly with the help of some external conditions, such as flapping wings invented in the past and the development of technology, and more convenient tools may appear in the future. But the sky is not what we think.