In “I Wandered Lonely as a Cloud”, Flowers are spring flowers and Wordsworth uses them as a physical thing that refers to an idea or emotion for youth. It is romanticized but in old age the mind dwells mostly in the past, which the poet does at the end of the poem. Although on the nature of the poem it is in reality about growing old and having memories of youth.
Absence are excuse for school
Thesausarus is as same as a dictionary, just has some more words.
An audiobook is also not that useful.
So I would say that an Encyclopedia an example of a multi media source.