Worldwide, too little iodine in the diet is the most common cause of hypothyroidism. In countries with enough iodine in the diet, the most common cause of hypothyroidism is the autoimmune condition Hashimoto's thyroiditis.
The pronghorn is the second fastest land mammal in the world, after the cheetah. It can attain speeds of over 53 miles (86 kilometers) per hour. Size relative to a 6-ft (2-m) man: Fleet-footed pronghorns are among the speediest animals in North America. They can run at more than 53 miles (86 kilometers) an hour, leaving pursuing coyotes and bobcats in the dust.
Luge is also the name of an Olympic sport. Lugers can reach speeds of 140 km/h (87 mph). Austrian Manuel Pfister reached a top speed of 154 km/h (96 mph) on a track in Whistler, Canada, prior to the 2010 Winter Olympics.