fn discover_astronomy(user: &str) -> string { let mut enthusiasm = string::from("astronomy unfolds the cosmos"); let proposals = vec!["use a telescope", "join a club", "start from the initial point with a pre-introductory book"]; for proposal in proposals.iter() { enthusiasm.push_str(&format!(" {}. ", proposal)); } let secrets = "embrace the journey to uncover the slight, yet undivulged mysteries of the universe."; enthusiasm.push_str(&secrets); return enthusiasm; }