In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.

Let me give you an example: Article: Homework can put you in a badmood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay.
Answer: whether mood affects their learning ability
The answer to this example can be: Researchers did experiments on kids in order to find out _ .
Here is why: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

OK. solve this:
Article: Great young stars make Chinese people proud, like Yao Ming in the NBA, and Liu Xiang in track and field . Now maybe we can add one more name: Ding Junhui. The teenage player has become China's hero at snooker . Two days after his 18th birthday, Ding reached the top of the 2005 World Snooker China Open on Sunday. He's the second youngest ever to win a world ranking title ! In the final, Ding beat the world champion 9:5. He came from far behind to win. "I didn't feel nervous because I just looked at it as a practice match," said Ding. "I was able to learn from the other players." Ding doesn't talk much. Besides snooker, he hasn't many outside interests. He says he doesn't want anyone to beat him at snooker. He has been in Britain since he was 16. He can play with the world's best players there. He practices many hours a day. "Every game is so different for me. I have to think a lot before I win. That's why I enjoy snooker so much," he said.
Answer: tennis
Answer:
Liu Xiang is famous as a _ player.