When light from a flashlight is moved quickly back and forth on a wall in a darkened room, it can appear to observers that there is a trail of light moving across the wall, even though physically the light is only in one place at any given time. This experience is an effect of memory that occurs because of .

i'll just take the points xd

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.

rain should be the answer.

money is the anwser i think