I would say 1. The light bulb because candles were far more of a fire hazard and a lot less light 2. Electric heater because again a lot less of a fire hazard and less prep work 3.electric refrigerator because you could safely store food for a long time with out spoil and or deep freezer for the same reason. Edit: some of this you might want to reword.
The answer would be immagrants started coming in to the US
Answer:
South America
Explanation:
South America separated before North From The Super Continent Pangea
Little to no safety regulations and many child workers.
Johannes Gutenburg created the printing press during the renaissance. It was important because it made the mass production of printed materials possible. It also lead to a much wider dissemination of knowledge and literacy throughout the socioeconomics classes.