英语听力:探索发现

They huddle and turn to face the threat, a giant short-faced bear. Faced by a wall of horns, the bear moves on to sniff out a less daunting meal. Occasional blizzards are another harsh reality of living in Beringia, but the drifting snow may at least

发表于:2019-01-23 / 阅读(174) / 评论(0) 分类 探索与发现2012年

Musk oxen and arctic hares are well-insulated against the cold as are the largest grazers of them all, the woolly mammoths. This herd is regrouping, ready for a long day feeding on the grasses beneath the snow. Mothers need to keep milk flowing for t

发表于:2019-01-23 / 阅读(157) / 评论(0) 分类 探索与发现2012年

But back then, they had serious competition from the giant short-faced bear. The short-faced bears bone chemistry reveals it was a carnivore and up to a ton, probably the largest meat-eating mammal that ever walked the earth. On its long legs, it ran

发表于:2019-01-23 / 阅读(164) / 评论(0) 分类 探索与发现2012年

For these baby animals, it was a race to grow up over the brief summer to be tough enough to face the winter. One young animal that died in its first winter was discovered in the permafrost of an Alaskan gold mine. Recreated here are the best-mummifi

发表于:2019-01-23 / 阅读(191) / 评论(0) 分类 探索与发现2012年

Arctic ground squirrels hibernate like other small mammals, but with a unique twist. They can lower their body temperature right down to almost minus 3 degrees centigrade. But thanks to a biochemical super-cooling process, they dont actually freeze.

发表于:2019-01-23 / 阅读(119) / 评论(0) 分类 探索与发现2012年

Small ears also help to minimize heat loss, the opposite effect of those huge heat-dispersing ears of their relatives, African elephants. Other Beringia animals have more than a fur coat to help them cope with cold. This skull belongs to the bizarre-

发表于:2019-01-23 / 阅读(141) / 评论(0) 分类 探索与发现2012年

At its maximum, the ice covered nearly six million square miles. And in places, it was up to two miles thick. The ice blanket was punctuated only by occasional islands of rock, the peaks of the very highest mountains. Though Beringia itself remained

发表于:2019-01-23 / 阅读(122) / 评论(0) 分类 探索与发现2012年

The fact that both horses and mammoths were here suggests these forests werent. It seems that, 14,000 years ago, Beringia was a huge expanse of open grassland. This unique habitat of cold, dry grasslands is known as mammoths steppe. But thats not how

发表于:2019-01-23 / 阅读(166) / 评论(0) 分类 探索与发现2012年

This is Alaska today, a wetland of forests, boggy tundra, lakes and rivers rivers that still churn out fresh clues to the Ice Age past. This is a brick-sized tooth, and it belong to a woolly mammoth. Its narrow ridges of enamel tell us more about how

发表于:2019-01-23 / 阅读(149) / 评论(0) 分类 探索与发现2012年

The answer lies in the effects of North Americas immense and fluctuating ice sheets. As they grew, they locked up so much water that the sea levels began to fall. The Bering Sea between Asia and North America began to drain away, leaving a bridge of

发表于:2019-01-23 / 阅读(138) / 评论(0) 分类 探索与发现2012年

Bears have long claws, but they get worn down by the daily grind, moving around and rooting for food. They are just not sharp enough to rip into the bisons hide. To solve this puzzle, we need to look to Africa. African buffalo are similar in size to

发表于:2019-01-23 / 阅读(127) / 评论(0) 分类 探索与发现2012年

In one remarkable discovery recreated here, the head and hide of a large carcass was exposed a unique opportunity for scientists to tap some Ice Age secrets. The remains were of an extinct steppe bison, a longer-horned relative of the North American

发表于:2019-01-23 / 阅读(127) / 评论(0) 分类 探索与发现2012年

Of all these creatures, the woolly mammoth is the undisputed symbol of the Ice Age. But what do we really know about how this giant lived. How did it use its massive spiral tusks? Modern-day elephants, the mammoths closest living relatives, may provi

发表于:2019-01-23 / 阅读(162) / 评论(0) 分类 探索与发现2012年

Away from the herd, the dominant male mammoth is distracted from his usual routine, today he has a more urgent priority than food, a younger challenger that wants to take his place. This ritual clash of tusks will decide the future for them both. The

发表于:2019-01-23 / 阅读(151) / 评论(0) 分类 探索与发现2012年

The Yukon and its neighbor, modern-day Alaska, were once part of the land that was Beringia. Stunning though this region is today is just a shadow of the world that was encountered by the First Americans. Underground, the soil is frozen solid, as it

发表于:2019-01-23 / 阅读(128) / 评论(0) 分类 探索与发现2012年

By searching for evidence that still survives today, we reconstruct the landscape and the wildlife of prehistoric North America. During the last Ice Age, massive glaciers covered half of North America. But to the far northwest, there was a land that

发表于:2019-01-23 / 阅读(137) / 评论(0) 分类 探索与发现2012年

21st century, North America, where people have reached even the remotest corners of the continent, and pushed back the boundaries of modern technology. But it isnt so long since humans first set foot here about 14,000 years ago. And back then, North

发表于:2019-01-23 / 阅读(201) / 评论(0) 分类 探索与发现2012年

On Good Friday 1014, the opposing forces faced each other at Clontarf, outside Dublin. There were two Irish armies, but both with their Viking allies. Of these Vikings it was said they carried arrows anointed and browned in the blood of dragons. The

发表于:2019-01-23 / 阅读(123) / 评论(0) 分类 探索与发现2012年

Brian did not see himself as a king among equals but as high king of all Ireland, and with a mighty army he set about trying to control the island. In the only statement of his that we know about, he describes himself as Imperator Scottorum, Emperor

发表于:2019-01-23 / 阅读(131) / 评论(0) 分类 探索与发现2012年

By the 11th century, the Vikings who had settled in Ireland, the Hiberno-Norse, had been here for over a century and a half. Theyd intermarried, become Christian and formed local alliances. Theyd founded thriving port cities like Waterford, Wexford,

发表于:2019-01-23 / 阅读(138) / 评论(0) 分类 探索与发现2012年
学英语单词
andres martinezs
archivolts
association list
baccalaureate gown
back pressure regulator
be talented with
bisporangiate
blackout technique
bowde
bulbas
buoy mooring
chamfron
changeover contact
clap skate
closed marginal geosyncline
cloverleaf grade separation
colored warp
crurophilia
cymophanes
direct-view kinescope
disintegration electron
dxrt
E-Tolls
echistatin
enactize
favorable balance of payment
FET humidity sensor
five-stage
fly cylinder
fortifier
Geising
glucopyron
graduated bushing
half-bright washer
hardware assembler
heat pump plant
Herzog, Chaim
hot film
IDI (improved data interchange)
image restoration
inorganic pigment
interaction cycle
janapa
jimador
ladewig
lattice swing bridge
Libia
liftins
lover boy
macrocyclops albidus
measurement of coordinates
meringue pastry
metasternal orifice
mindbody
mixture yarn
more-stable
musical clapping board
N-line
nounou
on-board date
orbital decay
output shaft
palaeocommunity
phantasmatic
piccaninnies
pleural villi
polar coordinates system
powder cap
power source van
professional society
proof beyond reasonable doubt
ptosis of upper lid
Qianjin District
radix paeoniae alba
rations
relaxosome
rural hygiene
sidenhand
sintered electrode
spherical lathe
squishop
steam heats
stookie
stowages
straight roller bearing
styrene acrylic exterior wall coating
Sφrvestkapp
textual research
tipler
tokaji
took
Tricarpelema
trobling
Tuberculum conoideum
TUIP
ungenotyped
usurarious
wallas wallas
weak-flutter cyclotron
Wikiversity
WTS (word terminal synchronous)
Ziziphus jujuba