What they say seems radical，but in fact not radical at all.Laughter can really bring us a lot of benefits.First，laughter has a similar effect of physical exercise.It speeds up our heart rate，increases our blood pressure and quickens our breathing.It also makes our facial and stomach muscles work.In fact，it is a kind of “jogging” on the spot.Next，laughter is a kind of pain relief.When we laugh，we produce a kind of chemical material in our body that helps us to relieve pain.In addition，laughter stimulates our immune system，preventing us from being infected by diseases.Third，laughter improves our state of mind and affects our entire physical well beings.Laughter helps us feel healthy and alive.Each time we laugh，we feel better and more content.