Answer:
The International Astronomical Union (IAU) has accepted 88 constellations in the sky.
Explanation:
Constellations has been used since the beginnings of civilizations and each one of them named them as they considered appropiate. It means Greeks' constellations were different than the ones described by Chinese, so it was necessary to gather all these constellations and make a great record with all of them, but there was a problem: Some constellations from different civilizations overlaped because they shared the same stars. There was necessary to put some order on this and that is when in 1922 the International Astronomical Union (IAU) defned a set of 88 moderm constellations that would become the international standard to look at the night sky. Each one of them is unique and does not share stars with the other constellations.
The formula for working out speed is distance ÷ time.
55 km ÷ 2 hours = 27.5 km/h (average speed for first part of journey)
52km ÷ 5 hours = 10.4 km/h (average speed for second part of journey)
(27.5 + 10.4) ÷ 2 = 18.95 km/h (average speed throughout the journey)
Answer: 1. Carbon dioxide is not an air pollutant
Explanation: it can be toxic and or safe
