A 7-year-old from Belgaum in Karnataka, India, has entered the Guinness World Records for being the lowest ever limbo skater, achieving a roller-skating height of just 25 cm over a distance of 10 metres.
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Mr Kim has made two recent visits to China.
The study looked at the development of 422 children over the course of eight years.
The president said they will come into force if China refuses to change its practices.