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What is the singularity of the universe? Is it a point 
The singularity of the universe, or the initial singularity, is a state predicted by some big bang theoretical models before the big bang. In this state, the space of the universe is "0" dimensional, and there is no space, and the cosmic radius is close to zero. Although we call it "point", it does not mean that it is a physical entity with length, width and height, but that it is a pump -
How plants pollinate 
Self pollination and cross pollination The main pollination methods of sexually reproducing plants can be divided into three types: self pollination, cross pollination and cross pollination. Self pollination: the pollen of the same flower spreads to the pistil stigma of the same flower, or the pollen of the same plant spreads to the pistil stigma of the same plant, such as rice, wheat, etc. Cross pollination: The pistil stigma receives pollen from different plants or flowers. Cross flower -
Radio wave source 
Cosmic radio sources are celestial bodies that emit strong radio waves in outer space. Radio radiation comes from hot gases, electrons that spiral in a magnetic field, and atoms and molecules that emit specific wavelengths in space. Radio emissions come from various sources. These objects represent the most extreme and energetic physical processes in the universe. In 1932, radio astronomy -
Why do cat's eyes glow In fact, the cat's eyes do not really shine, but show a phenomenon of light. This phenomenon is called "cat's eye glow" or "cat's eye reflection". The reason why cats' eyes look luminous is that they have a special structure called "reflective layer". This is a structure behind the eyes of cats, which is composed of cells and tissues. Its main function is to increase -
What is Nazism? 
Nazism (German: National socialism, which means national socialism or national socialism), often called "Hitler fascism" (German: Hitler fascism) in Europe in the 1930s, is a form of fascism, referring to Adolf Xi from 1933 to 1945 -
What are the three views 
The term "three outlooks" is often used in Chinese culture, which refers to a person's basic values, world outlook and outlook on life. This concept emphasizes the influence of a person's values, ideas and moral standards on his behavior and judgment. Although there is no fixed definition, it is generally believed that "three outlooks" refer to the following three aspects: these "three outlooks" influence each other and shape together -
Why should flowers be watered 
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Tencent cloud IM offline callback timeliness description 
Function description The App background can view the user's online and offline behavior in real time through this callback, including: Precautions The real-time nature of the scenario callback that may trigger this callback Android/iOS/PC For most cases, the change of user status can be sensed in real time, so that the callback can be triggered in real time. For example, there is only one special case -
1080p? 2k? 4k? Silly and unclear (comparison table) The following is a comparison table of common video resolution parameters. It should be noted that these resolution parameters are generally used in high-end video production, game development and other professional fields, and the corresponding hardware equipment and bandwidth requirements will also be higher. Moreover, not all application scenarios need such a high resolution, and the specific resolution depends on the specific needs and circumstances. Sometimes -
Why Alcohol Can Sterilize 
The reason why alcohol can be sterilized is that alcohol can absorb the moisture of viral protein, make it dehydrate, denature and solidify, so as to kill the virus. If high concentration alcohol is used, the virus protein will be dehydrated too quickly, so that the virus surface protein will first denature and solidify, forming a solid envelope. On the contrary, alcohol can not penetrate into the virus well, so as to affect its killing of the virus