4、ddivingintotheseafromthetopofhighcliff. Whydopeopletakepartinsuchactivitiesasthese?Somepsychologistssuggestthatitisbecauselifeinmodernsocietieshasbecomesafeandboring.Notverylongago,diseasescouldnoteasilybecured,andlifewasacontinuousbattleforsurvival.。 No