doubt in universe

Hi

I have created a universe on the top of the bex query, in the query i have various characteristic like CID,MID, revenue, calyear and calday.

but when i created the universe, for CID i have got L00, L01 and under L00 i have 4 keys .

My doubt is why so many objects are created for only one characteristic in bi.

Please see the below screenshot .

Please help ASAP.

tnx,

praveen.