英语听力：自然百科 行星旅行指南：火星 Mars—1

Have you ever fantasized about going somewhere special? Somewhere far from crowds, off the beaten track. Somewhere out of this world? Is it time to catch a rocket to the Red Planet? Mars is filled with mysteries, Volcanoes 75,000 feet tall, huge cany

英语听力：自然百科 行星旅行指南：火星 Mars—3

Could life have been forged in the same way on both planets? When we sent the first probe to investigate in the 1960s, almost anything was possible. Originally in the popular imagination we thought that Mars might be inhabited by whole civilizations,

英语听力：自然百科 行星旅行指南：火星 Mars—4

Therere some basic things you should know about Mars before leaving home. Most days will be clear, and sunny and cold. The average temperature on Mars is as bitter as midwinter in Antarctica. And about half the diameter of the earth, Mars is a handy

英语听力：自然百科 行星旅行指南：火星 Mars—5

In the four decades since our robots first arrived, the once fuzzy ball at the end of our telescopes has steadily focused into a red planet we can understand, and it is not a welcoming place. The problem is the atmosphere is so thin and cold that wat

英语听力：自然百科 行星旅行指南：火星 Mars—6

Steve Squyres Martian odyssey has taken him from pole to pole, visiting those places on earth that share at least some of the same characteristics. They are extremely dry, extremely cold or extremely dead. Death Valley is one of his favorites. This i

英语听力：自然百科 冰冻星球 前往地球尽头—16

The seal is now what the killer wanted, but the hunt is far from over. They need to wrap their prey by the tail while avoiding its snapping jaws. Only them will they be able to pull it down and drown it. Side swipes create farther underwater turbulen

英语听力：自然百科 冰冻星球 前往地球尽头—17

Exhausted, it no longer has the energy to pull itself to safety. And the killers are moving in. Game over. Although such team hunts are rarely seen, scientists believe they may be the most complex ever documented in the natural world. They were first

英语听力：自然百科 冰冻星球 前往地球尽头—15

The randoms of the sea ice are occupied by sun- bathing seals that have been here all winter. But the new arrivals're following the retreating ice edge and they have come here to hunt. Killer whales, the oceans' top predator. Killers are like wolves,

英语听力：自然百科 冰冻星球 前往地球尽头—14

Every summer over 40 million penguins take to the southern ocean to feed. They're joined by thousands of whales，minks are the most numerous. They all come here to harvest the richest ocean on earth. Carrying on south, we have our first glimpse of t

英语听力：自然百科 冰冻星球 前往地球尽头—18

The relative of the woodlouse is the size of dinner plate. And this so- called sea spider has legs that expand half a meter. Now it's explorer's own revealing other worlds that lie hidden beneath the ice on land. These smoking tars are the gateway to

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—14

elusive peak. -Come on. Let's get one last view. Well, that last gravel was worth it. -It was. -So what about 2,500 meters up here which is about 8000 feet？What's this summit called? －Doesn't have a name. -Doesn't have a name? -No. Doesn't have a

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—13

This is the halfway point of my walk today. It's been three hours since I started it out, some ideal spot for rest. I'm finally in the upper Berg.-So this is where people do in origins. -Yes. -Now I wish it's today though. I've come to realize this i

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—12

-Oh Julia,take a good look on the moutain.This is the last time you gonna see a full view of Cathedral Peak up until we get very close to it.And the best.So enjoy it.-How can you not enjoy it.-Enjoy it.Take it all in.-Nice cool bit of cloud. There's

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—11

An unexpected break in the weather means I am able to make one more stab at the summit. -It's difficult to believe this is the same spot as yesterday without the rain. You can actually see. And look at that vista! With the spring back into my stab, t

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—9

Day two, and rather worryingly, the weather doesnt seem to be improving. It also requires a painfully early start. Its an 18-kilometer round trip from the hotel to the summit, which most hikers tackle in one go, averaging eight to nine hours of stead

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—8

It was a very thought of wandering these mountains that first attracted Brian. He's remained a firm fan even since. He's even written a book about the hotel's history and his experience here.-It's so different from anything else you can find anywhere

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—7

For the Bushmen, it was this animal approaching that landed them in serious trouble. Zulu farmers chased the San further and further into the higher mountains, eventually pushing them out of the Drakensberg all together. -It is amazing to think that

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—6

Ok, Jules, I didnt make you walk all this way for nothing. Good. Ah these! So cave paintings. Yes, yes. These are San paintings. You may know them as Bushmen. The San Bushmen. Yes. Youre looking at basically the history of Drakensberg and we call it

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—5

All ready in my walk, I can see how changeable conditions here can be. A build-up of clouds often leads to thunderstorms in the afternoon, a bit of problems for walkers like me, but it does add us an air of mystery to the place. Did you know that, ap

英语听力：自然百科 徒步南非之德拉肯斯堡山脉 The Drakensberg—4

I'll steadly wire my way up, the Mbambonja Valley. Day One finishes with the welcome site of Cathedral Peak Hotel by overnight spot. The next day my climb follows the traditional walker's route. After swinging around into a hidden valley, my walk ste