1.The metric system is a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10.Metric units of length are easy to use because they are based on multiples of 10.
2.You can immerse the solid in water and measure the volume of the water displaced. The solid cannot dissolve in water.
3.A degree on the Fahrenheit scale must be smaller because there are 180 degrees between freezing and boiling as compared to 100 degrees for the same range on the Celsius scale.
During the early days of the Earths life there was no oxygen but there was plenty of CO2 which the autotrophs took and used as food while discarding the excess which was the oxygen.
