Answer: 
The Short Answer: Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
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Answer:
The first flowering plants appeared in the Mesozoic era, not the Paleozoic era.
Explanation:
The Mesozoic era was an era where numerous organisms started to develop in very unique and more advanced ways, both the animals and the plants. In the last period of the Mesozoic, the Cretaceous, the first flowering plants started to appear on the scene. This was revolutionary trait of the plants, and soon these plants started to occupy more and more space and became one of the dominant organisms on the planet. Other important evolution that took place in this period are the appearance of the dinosaurs and the mammals, both becoming the dominant animals on the planet, first the dinosaurs, after that the mammals.
 
        
                    
             
        
        
        
Answer:
4.5 meters is your Answer goood luck please give 5 star 
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Answer:
Ultraviolet wave
Explanation:
Ultraviolet waves would be best used to sterilize a surface expose to bacteria because it will completely destroy them. 
Most medical equipment are usually sanitized by using this rays because the DNA of most bacteria can be innervated upon exposure to these ray. 
Ultraviolet rays are energetic and more powerful than the normal visible light and subsequent long wavelength radiations. 
Generally, ultraviolet rays is a very harmful electromagnetic radiation.