pbr More than 10,000 people have set a new Guinness World record for human dominoes in China's Inner Mongolia.br ppbr They toppled a record set a decade earlier in Singapore by more than several hundred.br ppbr They were being closely monitored thoughout by Wu Xiaohong from Guinness World Records attempt: "The challenge of this domino activity was successful, and now the record is 10,267 people, and it is a new Guinness World Record."br ppbr The rules were strict; all participants had to go backwards in 5 seconds and they could not sit u p afterwards.br ppbr The 10,276, mostly students, sat cross-legged and fell backwards in a line that snaked across an enormous square. It took them 1 hour and 20 minutes to set the new record.br ppbr They had been training for four hours a day for three days to get ready for the event.