index return character

例句：

1. 1. The index of the book is on the back cover.
   这本书的索引在封面背面。
2. 2. She used her index finger to point to the answer on the board.
   她用手指指向黑板上的答案。
3. 3. The index of the dictionary indicates that the word is spelled "golden."
   字典的索引表明这个单词拼写为“golden”。