国际交流英语视听说B2U5.ppt

Listening 1 ;Listening 1 ;Listening 1 ;Listening 1 ;Listening 1 ;Listening 2 ;Listening 2 ;Listening 2 ;Listening 2 ;Listening 2 ;Narrator: Speed ... strength ... and power. Thousands of years before humans invented cars and airplanes, it was the horse who allowed us to go faster, go farther, and explore the world. Horses belong to the family of mammals called Equidae, along with zebras and donkeys. Like their close relatives, horses adapted to live in open country, eating grass, and using sheer speed to escape predators. They’re highly social and live in herds, which also helps protect against enemies. At first, humans were just one of the many hunters that preyed on the horse. But some 4,000 years ago, in central Asia, everything changed. ;Whether it was inspiration ... or an experiment ... or a teen-aged game, someone jumped onto a horse’s back. From then on, human history was set to the pounding sound of horses’ hooves. Whether they were conquistadors or cowboys—they owe their adventures to the same animal. Horses first lived in the forests of North America. About a million years ago, some crossed land bridges, spreading to Asia and Europe. These pioneers saved their species. About 8,000 years ago, either climate change or overhunting by early humans did its damage—and the last horses in America died out. Horses sailed back to their native land in the 1500s, carried in the ships of Spanish explorers. Soon Native Americans were trading with the Spanish, eager to own these amazing new animals. ;The descendants of their horses live on, in wild herds of mustangs, which live in the American West today. As horses became valuable workers, people began to breed them for different jobs. Over a hundred different breeds of domestic horses are now recognized, but they all belong to the same species, Equus caballus. Horses are classified based on their height, which is measured in hands—a unit of four inches, or literally the width of a human hand. Ponies are simply smal