Which statement best describes the motion of air particles in a sound wave? A. They move all around the wave.
B. They move in the direction opposite to that of the wave.
C. They vibrate at right angles to the wave.
D. They vibrate parallel to the wave.

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

i would think it's food chain

your answer is c! hope this : )