When did humans first appeared on earth

How does friction with the atmosphere affect the speed of an artificial satellite

(99 points) be serious! how do farts work? how do you fart without it stinking? serious answers only

How does the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents.earth's tilt causes the ocean to move because of gravity.earth's tilt and its rotation cause currents.earth's tilt causes uneven distribution of salt which causes currents.