Which one means VERY CLEAN?

I taught social studies to children at a cram school. I like my students.

Composition: A Bus Adventure While Mom usually drives us everywhere, buses here are a convenient way to get around. Last week, she decided it was time for me to learn how to ride them properly. First, I dug through my piggy bank (coins are becoming rare these days!) to find the fare. Standing at the bus stop, the route map seemed nonsense. Without Mom's help pointing out the correct bus, I would probably have been headed who-knows-where! Luckily, buses here aren't usually crowded except for rush hour. My trip to the park was smooth sailing. The seats were spotless, and the air conditioning was even stronger than most malls, with no trace of odor smells. And the most classic cliché that I had went over in my mind a million times didn't happen at all, like the chance to offer a seat to an elderly person. There just weren't any, and most seats were empty! Overall, my first bus ride wasn't bad at all. Next time, I'll tackle the route map and explore the city by bus! Maybe I'll even get to offer someone a seat someday.

Are there any incorrect pronunciation or expression this record?