Read carefully and answer the questions!

Ara: "Good afternoon, Mrs. Tina."

Mrs. Tina: "Good afternoon Ara. What are you doing?"

Ara: "I'm looking for a book. Could you do a favor for me?

Mrs. Tina: "What is it?"

Ara: "I need a book about science. Would you mind showing me it?"

Mrs. Tina: "No of course not. Can you look for it on the shelf over there?"

Ara: "Umm.. I have searched it but I haven't found it. Would you please took for it together?"

Mrs. Tina: "I have two books of science. Both of them are "My body science" and "Philosopher look all science". Do you like both of them?"

Ara: "Really? Can you lend me the second one, please?"

Mrs. Tina: "I'll lend you if you give it back soon."

Ara: "Certainly. I'll return it immediately. Thank you."

Mrs. Tina: "You're welcome."

How many books does Mrs. Tina have?