Birds that fly have lightweight bones, some of which are hollow. how might this unique body structure benefit the bird?

Body systems are not completely independent they integrate and work together describe one example of the integration between body systems

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?

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?