题目

Young people are being invited to take part in a photography competition.The Rotary Clubs (扶轮社) of Formby have organized the free event for young photographers who live in,or are at school in Formby.Children taking part must have been aged 16 or under.There is a senior section for children aged between 12 and 16 and a junior section for those who are 11 years old and under.Children taking part can submit (提交) up to three photos and there is no set theme.There are cash prizes for both the senior and junior sections,with $ 30 for the first place,$ 20 for the second and $15 for the thir一个几何体的三个视图都是全等的正方形，则这个几何体是________．