Hmm...
Memory?
Because:
<em>
Today I will live my memory, tomorrow more memories will come. As time passes, memories aren't easy to remember, it doesn't take space, and it's only in one place, which is the pass. Memory is what we saw, but not see anymore.</em>
Maybe this helps:
Conjugation of 'Sing'
Base Form (Infinitive): Sing
Past Simple: Sang
<span>C.homogeneous mixture</span>