The excerpt above is from "The Perks of Being a Wallflower". The lines are written in sharp honesty and vulnerability. If it is written in an ironic tone, it means that the narrator is not satisfied with his life. Theme of the story would become different because if would lose the sincere type of narration of the boy who is coming of age.
Answer: Bicycles enable African girls to attend school despite their busy schedules.
The language system is semantics. "Coke" v.s "Sprite." are two different words, so we are focusing on a word. When Anna paused, she was confused because to Melinda, A Coke means a Sprite in her vocabulary. She wanted to confirm the same meaning. Semantics involves a changing meaning depending on the person. She is visiting from Alabama, so the meanings may have chosen just like dialects. Thus, it cannot be phonology/morphology, syntax, or pragmatics.
