Read the excerpt from Barrio Boy by Ernesto Galarza. Hanging from a cord attached to the middle of the ceiling there was an electric bulb, low enough for an adult to reach and turn the black switch. I realized that this was our own electric light for us to turn on and off as we pleased. I pushed a chair under it and after some instruction from my mother proceeded to create lightning in the room by turning the switch as fast as I could. Which effective technique does the author mainly use to write this excerpt?