IF YOUR ON PLATO THE ANSWER WOULD BE ..............C...........
This invention was a commercial failure. Edison resolved that in the future he would only invent things that he was certain the public would want. ... This gave Edison the money he needed to set up his first small laboratory and manufacturing facility in Newark, New Jersey in 1871.
found at: https://www.nps.gov/edis/learn/historyculture/edison-biography.htm
When cool air sinks it forces warm air to rise is a example of convection.
Stage 3 because the person fev1 level is go down not up
