What characteristic makes marine mammals different from other marine animals? They all give birth on land.
They live only in the ocean and cannot leave the water.
They are carnivores that eat mainly fish.
They breathe air through lungs.

In which state was more than 100 billion tons of coal mined in 2005?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal response by in order to it's core temperature.