For example,  when we are watching a scary movie and we can feel very scared even  though we are not even in danger. Even when we thing we have seen  something, for example, a ghost, when we really haven't. So the  answer is: the human brain is the most powerful thing on the earth. Christopher Gerstle.
The grizzly bear is a North American subspecies of the brown bear that once roamed the Great Plains.oday, only about 1,000 grizzlies remain in the continental U.S. Identifiable by its distinctive hump and the grayish, or grizzled, tips of its fur, the mighty grizzly bear has a terrific sense of smell and can run at speeds of up to 30 miles per hour.
The average length of a grizzly is 6.5 feet and the average shoulder height is over 3 feet. Adult males weigh 400-790 pounds on average, although some have been recorded with staggering weights up to 1,500 pounds. Grizzly bears have powerful front claws that measure 2-4 inches in length and can tear with ease.