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
amplypterus mansoni takamukui
analogue matrix addressing
apartus
aquae pura
asexual dwarf
auricular malformation
autoscripting
bac phan (tonkin)
bahut
biological pesticide
block polymer
Chmielnik
circumgyrated
contraction distortion
corroding agent
couponers
Deaf Smith County
Detrulisin
double plate balanced rudder
drum storage
error frequency
erythema multiforme exudativum
eunuchoidisms
fenced off
fishy odour
flame flower
fluorescent
flutier
free-well agreement
golden rod
grape blossom midge
gutter-snipe
hamburger press
hereditarian
hydrocyclone
hynix
hystero-oothecectomy
imperial seal
it is a wonder that...
jury steering gear
keying of entries
kinematics of rigid body
knife coarse file
La Communaute Financieve Africane
Larkhall
laryngeal cartilage scissors
Ljutomer
makovickyite
manager role
master group
mchardy
MD-BFP (motor driven boiler feed pump)
miniseries
MNO
nami
NFAP
nominal definition
non-chromatic
numina
odontocete
oour
pan mill
Perevolochnyy Zaliv
periodic dumping time-sharing
phethenylate sodium
picumnuss
Pirani gauge tube
planar osculating angle
polyvinyl insulated (cable)
positive meniscus lens
problemsolver
productivity of sinter
protoctist
reputed owner
second firing
second-level interrupt
shortage penalty
sicilies
social insurance trust funds
South-East Asia Treaty Organization
spring pad
sulphur tuff
superbold
supply-route
Teilhardian
title part
to trash
transient acceleration
Trichomycteridae
Tripitakas
trowelling plate
truncated cheque
Târgu Bujor
undeniedly
unsquashed
vasorrhaphy
vintage item
wall blocking
writing-box
yellow-stained cotton
you kiss your mother with that mouth