Respuesta :
The underlined words describe how the author is feeling and how he may need laughter because he has frustrations with work. I hope this helps.
The correct answer is "a monotonous daily routine".
Explanation: The line "My struggle is harsh and I come back," does indicate that his life at work is difficult, but he describes the earth as "unchanging" which is synonymous for monotonous. He is explaining that his lover's laughter brightens up a boring, constant world.