What aspect of this excerpt most clearly makes it as a work of modernism?

In this excerpt from "dover beach" by matthew arnold, which two lines or sets of lines suggest that the speaker has undergone a loss of faith? the sea of faith was once, too, at the full, and round earth's shore lay like the folds of a bright girdle furled. but now i only hear its melancholy, long, withdrawing roar, retreating, to the breath of the night-wind, down the vast edges drear and naked shingles of the world. ah, love, let us be true to one another! for the world, which seems to lie before us like a land of dreams, so various, so beautiful, so new, hath really neither joy, nor love, nor light, nor certitude, nor peace, nor for pain; and we are here as on a darkling plain swept with confused alarms of struggle and flight, where ignorant armies clash by night.

Imagine you have 24 hours to change into any sea creature. which creature would you choose to be? describe what you life would be like during your time under the ocean.

In this unit we learned about arguments and rhetoric. in an argument we use ,not informal language