Please choose the correct ending to complete the given sentence: Relationships: [header] How to keep a straight face [title] Take a deep breath. [step] It's impossible to laugh while you're inhaling. If you're afraid you can't keep a straight face, take a deep breath in and let it out slowly.

Ending1: Repeat this as many times as you need to until you feel like you don't need to laugh anymore. [substeps] Don't take a huge deep breath with your mouth open-it might be obvious what you're trying to do. Ending2: Relax your body and breathing is a powerful energy that often surpasses difficult situations. [substeps] Try a short run instead of a full workout. Ending3: Imagine that all of the air moving through your body is rushing away from you, escaping from your nose and onto your lips. Hold the breath in for as long as necessary, but don't let it go past your diaphragm. Ending4: When you're taking a breath, think to yourself: " i'm breathing deeply; this is the right moment to be laughing and no one will know i'm upset. " [substeps] Once the breath is inhaled, count to 5 as you begin to breath deeply in and out.

Answer format: ending1/ending2/ending3/ending4