The sky is blue because blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
Answer: Here is a few Gemini, Canis Major, Canis Minor , Orion Taurus.
Answer:
Using fossil fuels in factories, less people out using cars (so less exaust) and also less trash in waters so the evaporated water isn't so full of bacteria.
Explanation:
IDK if this is what you are looking for but, less bacteria and smoke and fossil fuels go into the air making the air cleaner.
I'm open to questions.
I'm guessing the United Kingdom.