Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to save electricity [title] Embrace natural light. [step] Open up your curtains and let the sun shine in! Using natural light whenever possible instead of relying on artificial light can greatly reduce the amount of electricity you use during the day. The same is true whether you work in an office or spend your days in your house.

Ending1: Adding natural lighting to your design can make your oxygen levels lower, decrease your chromatic signals, and boost your overall energy levels. [substeps] Sunlight also constricts energy, increasing energy expenditures. Ending2: [substeps] Try to move around whenever possible--otherwise, the best light source is outside. If you're physically unable to break a sweat in a hot environment, this can be a recipe for disaster. Ending3: Natural light tends to be safest when left alone for a while, and may help you sleep better, but not at night. [substeps] While there's no answer to this question, exposure to natural light might help you feel more rested and refreshed. Ending4: Exposure to natural light also increases happiness, , giving you an even greater incentive to raise the blinds. [substeps] Try to arrange your workspace so that natural light floods your desk.

Answer format: ending1/ending2/ending3/ending4