Give an example of something that has the characteristics of the "sublime" and explain why.

"The Solitary Reaper," one of Wordsworth's best-known poems, is an example of what he considered "the sublime" as well as an illustration of his own ideal of poetic writing.
In his preface to Lyrical Ballads, Wordsworth stated his intention to deal with "ordinary" subjects and to write verse in a style as close as possible to prose, or even to everyday speech. In this poem he describes a girl working in a farmer's field, cutting and binding wheat. He makes the point that, to him, this sight is more beautiful than the unusual, exotic sorts of things poetry has typically dealt with:

No nightingale did ever chaunt
More welcome notes to weary bands
Of travellers on some shady haunt,
Among Arabian sands.

The simplicity of the scene, and of the girl herself—both her beauty and her singing—has a nobility to it which, in Wordsworth's view, is lacking in conventionally poetic images. Rustic subjects and nature, in the new Romantic mindset, are the ultimate form of the sublime precisely because they are simple, natural and uncorrupted. The simplicity and directness of his language here, and in his poetry in general, are the formal equivalent of the content with which Wordsworth deals. His verse sounds similar to the way people talk in real life. Two other well-known poems of his showing exactly these qualities are "The Thorn," and "Daffodils."
Though Wordsworth was in the forefront of the Romantic movement, his poetic ideal of the sublime, in both form and content, was not necessarily shared fully by the other Romantics, even his close friend and collaborator Coleridge. But it is safe to say that Wordsworth effected a revolution that changed English poetry forever.