Read the dialogue below and answer the questions confidently.

Jane: Please lend me a novel.

Lidia: I am sorry, the novel is being read by my sister.

Jane: Do you have another novel?

Lidia: No, I don't have any novel, but my sister has.

Jane: So what is your favorite book?

Lidia: I love comic. It is read every night before sleep.

Jane: May I see your comics?

Lidia: Yes, sure. Here you are. But Conan is being read by my brother.

Jane: No problem. Where did you buy these comics?

Lidia: Those were bought in Gramedia.

Jane: Does your sister like a novel so much?

Lidia: Yes, she does. Novels are collected by her. A novel is always bought in a month.

Jane: She's a novel holic.

Lidia: Yups. Do you want to go with me to the bookstore? I want to buy English book.

Jane: Why not! Let's go!

Why is a novel always bought by Lidia's sister in a month?