根据对话内容，完成下面短文，使其意思完整，首字母已给出。

Bill:  We'll have a school concert this Sunday. I can only play the drums.

Mike: l can play the piano and the guitar, but I can't sing. Who can sing?

Jack: I can sing and dance, and I can also play the violin.

Bill: OK, the concert will begin at 8:00 p. m. We must get to the school auditorium at 4:00 p. m.

Mike and Jack: OK, bye.

     Bill, Mike and Jack are talking about the school (1) c______. Jack can sing and (2) d______ and he can

also play the (3) v______. Mike can't (4) s______well, but he can play the (5) p______ and the (6) g______.

Bill can (7) o______ play the (8) d______. He asks them to get to the school (9) a______ 4:00 p.m. The

(10) c______ will begin at 8:00 p.m.

在数据库系统的三级模式体系结构中，描述数据在数据库中的物理结构或存储方式的是______。