A bird’s nearly hollow bones help it to .
A) store extra oxygen
B) deliver oxygen to its cells
C) be lightweight in the air
D) defend itself against predators

the answer is c most of the fortnite players usually buy v bucks to get the battle pass and other cosmetics but some players who are referred to as "no skins" don't   buy skins and are usually noobs.

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they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate