Please explain ecosystem productivity

Which of the following areas have the highest population density? a) quebecb) united statesc) californiad) new york city

Which environment would most likely not contain fossils? a a thick deposit of cracked, dried mud b sediment deposited in a sandy river bed c intrusive rock formed from cooled magma d layers of sand accumulated for a century

How did the movement of soldiers during world war 1 contribute to the global influenza (flu) pandemic of 1918 to 1919, which killed millions of people