[填空题]
How many kWh of energy/. y.jdhu,aq r8thtff i2e w o3u cijmvg1::/( does a 550-W toaster use in the morning if it is in operation for a total of 15 min? At a costwo ::t vjgefhi tf/8(3m2u 1ic of $9.0\,cents/kWh$, estimate how much this would add to your monthly electric energy bill if you made toast four mornings per week.
energy $\approx$ kWh
cost $\approx$ cents/mouth
