本文作者： 21ST
The hottest gift this holiday season in the UK and the US has been a two-wheeled, self-balancing *scooter called a *hoverboard. It can be used either as a toy or as a transportation tool. But now the hoverboard craze may soon end because of safety concerns. It turns out that the trendy scooters may literally catch fire because their *lithium-ion batteries can get too hot.