The revelation of nature

Dragonflies can generate local unstable airflow different from the surrounding atmosphere through the vibration of their wings, while Wells uses the vortex generated by the airflow to lift himself up. Dragonflies can soar under a small thrust, not only forward, but also backward and left and right, and its forward flight speed can reach 72 km/h. In addition, the flight behavior of dragonflies is simple, with only two pairs of wings flapping constantly. Scientists have successfully developed a helicopter based on this structural foundation. When an airplane flies at high speed, it often causes violent vibration, and sometimes even breaks its wings, causing the airplane to crash. Dragonflies rely on aggravated wing moles to fly safely at high speed, so people follow the example of dragonflies and add weights to the two wings of the plane to solve the thorny problem of vibration caused by high-speed flight.

"Rat" has now become the natural enemy of human beings, where everyone shouts, but (Zodiac) rat is indeed the first; What is the reason? The first cooked food that humans eat is mouse meat; The craftsman found that it was first used for heating after ignition. In the coldest days, all animals return to their caves, and "human beings" gather in groups, or light bonfires in caves or sheltered places to warm themselves with fire to spend this idle cold day. At the same time, I am ready to endure hunger by burning fat. It also produced the first time that "human beings" used wisdom to resist the cold. When "human" is hungry to keep warm, rats are not lonely, and they come to people's bonfires in droves to harass people. When the wise man saw the mouse, he found that it was something to satisfy his hunger, so he got up and chased it down, but the mouse was not easy to catch. Their escape ability is first-class, so the mice are chased around, and some mice are forced to barbecue in the fire.