A:铁发生还原反应
B:铁发生氧化反应
C:铁是还原剂
D:铁失去电子
(____) They're on Shelf A.
(____) Well, let me help you.
(____) But I can't find the book.
(____) Where are the books about sports, please?
(____) Do you know the name of the book?
选文第⑤段中划线的“这些做法”具体指代的内容有哪些?