The task is about reading the given story and question, then finding an answer to the given question. Based on the passage provided and the given question, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Input: Consider Input: story: Art lovers around the world have thought about this question for so many years: what is the secret behind the Mona Lisa's smile? However, they can ask Mona Lisa herself in the interactive exhibition in Beijing. This exhibition brings the 500-year-old painting to life. Now Leonardo da Vinci's famous painting can move her head and wave her hand in 3D, and even answer questions. She can answer the questions about her life, her age and so on. But when she talks she doesn't speak Italian but Chinese like: "Da jia hao, wo jiao Mengna Lisha. Hen gao xing jian dao ni men." The new, digital picture of Mona Lisa is the center piece of the World Classic Interactive Arts Exhibition in Beijing. You can also see other world-famous paintings such as Leonardo da Vinci's Last Supper. Last Supper is another picture that they made alive with 3D. In this picture, Jesus can walk and talk with his believers . It took the organizer Wang Hui and over 400 digital artists in South Korea two years to make the picture, at a cost of around 50 million yuan. He says, "What's special about it is that it's the first time to use computer technology to make her speak and move." So what does the Mona Lisa say if you ask her why she is smiling?, question: What do people wonder about?

Output: the secret behind the Mona Lisa's smile

Input: Consider Input: story: Traditionally considered the last part of the Stone Age, the Neolithic followed the terminal Holocene Epipaleolithic period and commenced with the beginning of farming, which produced the "Neolithic Revolution". It ended when metal tools became widespread (in the Copper Age or Bronze Age; or, in some geographical regions, in the Iron Age). The Neolithic is a progression of behavioral and cultural characteristics and changes, including the use of wild and domestic crops and of domesticated animals.

The beginning of the Neolithic culture is considered to be in the Levant (Jericho, modern-day West Bank) about 10,200 8,800 BC. It developed directly from the Epipaleolithic Natufian culture in the region, whose people pioneered the use of wild cereals, which then evolved into true farming. The Natufian period was between 12,000 and 10,200 BC, and the so-called "proto-Neolithic" is now included in the Pre-Pottery Neolithic (PPNA) between 10,200 and 8,800 BC. As the Natufians had become dependent on wild cereals in their diet, and a sedentary way of life had begun among them, the climatic changes associated with the Younger Dryas are thought to have forced people to develop farming., question: What was the Neolithic considered?

Output: the last part of the Stone Age

Input: Consider Input: story: So, there was this kid named Jack that came up to my beanstalk one day. I couldn't believe my eyes, so I put down my ham sandwich I was eating and looked at him. I'm not sure what he thought he was doing there, but he sure did talk a lot. He kept asking me questions about this and then he asked me some questions about that and I was getting a little bit tired of all of the questions.

When I thought I wouldn't hear the end of everything, this Jack kid asked me about the one and only secret that I've always kept to myself. That no one even knew about! No, it wasn't about my golden guitar or even my goose that laid eggs filled with coins. No, he was asking me about my beans and their roots.

You see, I'm a giant and my job is to make sure the bean roots that we use to get down to earth are well protected and guarded. They're what helps us get down to the little person world when we need to. I became a little bit worried as the little kid asked more and more questions about my roots. I didn't want to tell him that my roots were hidden in the library!

I walked over to him to pick this little kid up to get him to quiet down about the bean roots, well, he got me with his little knife and I dropped him! Thankfully, he didn't get hurt or I would've been so sad!

He ran down the beanstalk when I chased after him. I guess he wanted to get back to his little people. I didn't follow him, but I sure hope he doesn't come back for my stuff., question: What happened next?
Output: I chased after him