diff --git a/src/exercises/day-2/book-library.md b/src/exercises/day-2/book-library.md
index 23954e9a..b113b0e2 100644
--- a/src/exercises/day-2/book-library.md
+++ b/src/exercises/day-2/book-library.md
@@ -25,14 +25,24 @@ Use this to model a library's book collection. Copy the code below to
     }
 
 {{#include book-library.rs:Library_len}}
+        todo!("Return the length of `self.books`")
+    }
 
 {{#include book-library.rs:Library_is_empty}}
+        todo!("Return `true` if `self.books` is empty")
+    }
 
 {{#include book-library.rs:Library_add_book}}
+        todo!("Add a new book to `self.books`")
+    }
 
 {{#include book-library.rs:Library_print_books}}
+        todo!("Iterate over `self.books` and print each book's title and year")
+    }
 
 {{#include book-library.rs:Library_oldest_book}}
+        todo!("Return a reference to the oldest book (if any)")
+    }
 }
 
 {{#include book-library.rs:main}}
diff --git a/src/exercises/day-2/book-library.rs b/src/exercises/day-2/book-library.rs
index 14dd6d17..16cf04b5 100644
--- a/src/exercises/day-2/book-library.rs
+++ b/src/exercises/day-2/book-library.rs
@@ -33,8 +33,9 @@ impl Book {
     }
 }
 
-// Implement the methods below. Update the `self` parameter to
-// indicate the method's required level of ownership over the object:
+// Implement the methods below. Notice how the `self` parameter
+// changes type to indicate the method's required level of ownership
+// over the object:
 //
 // - `&self` for shared read-only access,
 // - `&mut self` for unique and mutable access,
@@ -49,49 +50,34 @@ impl Library {
     }
 
     // ANCHOR: Library_len
-    //fn len(self) -> usize {
-    //    todo!("Return the length of `self.books`")
-    //}
-    // ANCHOR_END: Library_len
     fn len(&self) -> usize {
+        // ANCHOR_END: Library_len
         self.books.len()
     }
 
     // ANCHOR: Library_is_empty
-    //fn is_empty(self) -> bool {
-    //    todo!("Return `true` if `self.books` is empty")
-    //}
-    // ANCHOR_END: Library_is_empty
     fn is_empty(&self) -> bool {
+        // ANCHOR_END: Library_is_empty
         self.books.is_empty()
     }
 
     // ANCHOR: Library_add_book
-    //fn add_book(self, book: Book) {
-    //    todo!("Add a new book to `self.books`")
-    //}
-    // ANCHOR_END: Library_add_book
     fn add_book(&mut self, book: Book) {
+        // ANCHOR_END: Library_add_book
         self.books.push(book)
     }
 
     // ANCHOR: Library_print_books
-    //fn print_books(self) {
-    //    todo!("Iterate over `self.books` and print each book's title and year")
-    //}
-    // ANCHOR_END: Library_print_books
     fn print_books(&self) {
+        // ANCHOR_END: Library_print_books
         for book in &self.books {
             println!("{}, published in {}", book.title, book.year);
         }
     }
 
     // ANCHOR: Library_oldest_book
-    //fn oldest_book(self) -> Option<&Book> {
-    //    todo!("Return a reference to the oldest book (if any)")
-    //}
-    // ANCHOR_END: Library_oldest_book
     fn oldest_book(&self) -> Option<&Book> {
+        // ANCHOR_END: Library_oldest_book
         // Using a closure and a built-in method:
         // self.books.iter().min_by_key(|book| book.year)
 
@@ -108,30 +94,31 @@ impl Library {
 }
 
 // ANCHOR: main
-// This shows the desired behavior. Uncomment the code below and
-// implement the missing methods. You will need to update the
-// method signatures, including the "self" parameter! You may
-// also need to update the variable bindings within main.
 fn main() {
-    let library = Library::new();
+    let mut library = Library::new();
 
-    //println!("The library is empty: library.is_empty() -> {}", library.is_empty());
-    //
-    //library.add_book(Book::new("Lord of the Rings", 1954));
-    //library.add_book(Book::new("Alice's Adventures in Wonderland", 1865));
-    //
-    //println!("The library is no longer empty: library.is_empty() -> {}", library.is_empty());
-    //
-    //
-    //library.print_books();
-    //
-    //match library.oldest_book() {
-    //    Some(book) => println!("The oldest book is {}", book.title),
-    //    None => println!("The library is empty!"),
-    //}
-    //
-    //println!("The library has {} books", library.len());
-    //library.print_books();
+    println!(
+        "The library is empty: library.is_empty() -> {}",
+        library.is_empty()
+    );
+
+    library.add_book(Book::new("Lord of the Rings", 1954));
+    library.add_book(Book::new("Alice's Adventures in Wonderland", 1865));
+
+    println!(
+        "The library is no longer empty: library.is_empty() -> {}",
+        library.is_empty()
+    );
+
+    library.print_books();
+
+    match library.oldest_book() {
+        Some(book) => println!("The oldest book is {}", book.title),
+        None => println!("The library is empty!"),
+    }
+
+    println!("The library has {} books", library.len());
+    library.print_books();
 }
 // ANCHOR_END: main