Itissaidthatmostpeoplehavenotmorethan30friendsatanygive...
問題詳情:Itissaidthatmostpeoplehavenotmorethan30friendsatanygiventime,and400overthewholeoftheirlives.However,onsocialnetworkingsites,mostusershaveabout150friends.Ifthesenumbersarecorrect,thenfriendship...