Some might say they are off their trolley.
But to succeed in this race, you need to be in control of your senses as well as your vehicle.
Creativity and showmanship count as much as mechanical expertise in the Red Bull Soapbox Race.
This year's event in Hong Kong featured vehicles decorated as everyday items. The hotpot got applause but it was this skull-shaped entry that won over the judges.
off your trolley 瘋了
in control of your senses 理智的
BBC © 2013 非本網站內容BBC概不負責