What does a pedigree chart show? pls help!

What metric units would you use to measure the thickness of a key

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6

How does kepler second law of planetary motion overthrow one of the basic beliefs of classical astronomy