Definition: 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.
Input: Article: Nearly a thousand people laugh heartily together for half an hour every morning in a park in Shenzhen. Guangzhou Daily took a closer look at those happy people. They are members of a group named Laughing Club, and when they get together, all they do is laugh. Zhang Lixin, the founder of the club and regarded as the 'laugh leader', told the paper that laughing does him a lot of good. He started after he read some advice in a book and tried giggling after quarrelling with his wife to relax. After laughing for a few days, Zhang found himself more outgoing and relaxed. Soon his wife joined him, bringing the family more laughter and less bickering. When he got to know a kind of "laughing yoga" is good for the health, Zhang went to Bombay to learn from the locals and developed what he learned into more than 30 ways of laughing. The "lion bellow "is to shout with the fingers outstretched near the ears. There is the "open mouth laugh", the "bow-pulling laugh", the "welcoming laugh" and even the "quarrelling laugh", with different arm movements of laugh style. The "laugh movement" swept over Shenzhen in a few of months, attracting tens of thousands of people to join, and has been followed in nearby cities such as Guangzhou. Every morning at the lake front and at 8 pm on every Monday, Wednesday, Friday at the mountain peak square in Lianhua Mountain Park, club members gather to laugh and shout loudly.
Answer: want to relax themselves
Output:
The people in Laughing Club laugh because they _ .