If a layer of sandstone lies on top of a layer of limestone in which a 300 million year old fossil is found and there are no nonconformist the layer of sandstone must be

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

gravitational energy

electrical energy

kinetic energy

ligh energy

the answer is c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.