英语听力：自然百科 行星旅行指南：木星 Jupiter—9

This could be the most terrifying sight in the solar system: clear skies above a bottomless pit, an infernal drop into the depth of Jupiters endless sky. You may have raindrops evaporating into the hot interiors of Jupiter, but there is no ocean down

英语听力：自然百科 行星旅行指南：木星 Jupiter—8

Picture a suicide dive into the mysterious depth? Relax, Galileo's already done it for you. We separated the probe from the Galileo mother ship. We were flying in toward Jupiter, basically a ballistic bullet. The Galileo probe went in at an unbelieva

英语听力：自然百科 行星旅行指南：木星 Jupiter—7

If you are floating in a balloon, the center of the red spot might be rather calm. But you will be going fast, your balloon will be going faster than the hurricane winds, but it might be a smooth ride. This storm is a sigh to the halt, towering five

英语听力：自然百科 行星旅行指南：木星 Jupiter—6

When the space hardened Voyagers I and II flew past in 1979 on their way to the outer solar system, Jupiters great mysteries only deepened. How were these powerful magnetic storms generated inside a giant ball of gas? Why was one moon boiling with vo

英语听力：自然百科 行星旅行指南：木星 Jupiter—4

Jupiter is a planet that knows how to exert its influence on the solar system, and how to impress even the season traveler. You can fly around the earth in a jumbo jet in less than two days. Try this on Jumbo Jupiter and youll be in the air for three

英语听力：自然百科 行星旅行指南：木星 Jupiter—3

This giant gas bag is built from the flimsiest materials in the universe. But for all its squishy bulk, its a great little mover. Jupiter spins at such a breakneck speed that it bulges at the equator, so fast in fact that a day here lasts less than t

英语听力：自然百科 行星旅行指南：木星 Jupiter—2

Oh, man, thats incredible!.... A tour of the solar system wouldnt be complete without a visit to its largest planet, but with the grandest sights, biggest dangers and greatest mysteries all on the itinerary, it pays to brush up before blast off. Cons

英语听力：自然百科 行星旅行指南：木星 Jupiter—1

Life feeling a bit ordinary? Travel choices a bit tame? Head beyond the asteroid belt for an out-of-this-world experience. Welcome to Jupiter, home of high-adrenaline adventure. Plunge into its mysterious depth. You drop through the clouds, it would

英语听力：自然百科 黄石公园的夏天 Yellowstone—10

As soon as she feels it is safe, she settles to suckle and reassure them. Bison can shrug off this sudden change in the weather; they are after all built to survive the Yellowstone winter. But this tiny hummingbird is more vulnerable. Flowers damaged

英语听力：自然百科 黄石公园的夏天 Yellowstone—9

This pack seem prepared to allow their young a brief foray to experience the world beyond their den. But his high-octane lifestyle critically depends on the summer sun. And in Yellowstone, that's never a guarantee. In the mountains surrounding the pl

英语听力：自然百科 黄石公园的夏天 Yellowstone—7

Hot water scorches and drowns the roots of trees encroaching on the valleys. It can keep the forests in check and the rich pastures / open. Those pastures now produce the new grass needed to make rich milk and feed a bison baby boom. The few calves b

英语听力：自然百科 黄石公园的夏天 Yellowstone—6

As the migrating herds arrive in the plateaus river valleys, the spring is here. This is why they have made the journey after the famine of winter. Food is everywhere. Birds have flown in from as far away as the Arctic and subtropics. Canada geese jo

英语听力：自然百科 黄石公园的夏天 Yellowstone—5

As 6 months of snow and ice begins to melt, Yellowstone starts to come back to life. Cascading snowmelt swells the streams and rivers. It's a hazard that the migrating herds must cross. Young are barely up to the task. The Yellowstone river has incre

英语听力：自然百科 黄石公园的夏天 Yellowstone—4

Clues to why the herds are drawn to the Yellowstone plateau lie in its deep and unique history. This plateau is the created bowl of a huge sleeping volcano. And melting rock below the surface still pushes the land up to the cold of high altitude. But

英语听力：自然百科 黄石公园的夏天 Yellowstone—3

This mother bear's experience gives her family a good chance of survival until spring arrives. They will return again and again as the thaw releases more fish. On the warmer plains and valleys that surround the plateau, grazers are on the move. They

英语听力：自然百科 黄石公园的夏天 Yellowstone—2

The end of winter comes late to the mountainous northwest of the United States, and in particular, it lingers in Yellowstone. The heart of Yellowstone is a high cold plateau, 8,000 / feet up, surround by the spires of the Rocky Mountains. After five

英语听力：自然百科 黄石公园的夏天 Yellowstone—8

This pack seem prepared to allow their young a brief foray to experience the world beyond their den. Even in Yellow Stone it is extremely rare to see wolf pups like this. Before long they are summoned back into the forest by the pack. It will be wint

英语听力：自然百科 冰冻星球 前往地球尽头—7

This, Jakobshavn Isbrae, is the fastest flowing glacier on our planet, moving as much as 14 meters a day. As it advances, it destroys everything in its path, even cutting its way through Greenland's great mountain ranges on its drive downwards toward

英语听力：自然百科 冰冻星球 前往地球尽头—13

And fishing can be dangerous. A southern sea lion. It uses the speed of a breaking wave to catch up with the gentoos. Sea lions normally eat fish. So he is used to catching streamline swimmers. But the gentoos seem more than his match-up at sea. He m

英语听力：自然百科 冰冻星球 前往地球尽头—12

The Taiga forest marks the end of our journey through the Arctic from the frozen ocean down across the lands that surround it The other end of our planet, the Antarctic is starkly different. A frozen continent completely surrounded by ocean. Icebergs