冰期

But most significant of all, the jaguar has a tell-tale trademark. Instead of going for the neck or snout like most cats do, it kills with a crushing bite through the skull into the brain. This makes the jaguar prime suspect in this case. Even the gl

发表于:2018-12-03 / 阅读(167) / 评论(0) 分类 探索与发现2012年

These holes are the unmistakable hallmark of a violent death. Their shape suggest they were made by the teeth of a big cat, but which one? Today theres only one large cat in the region, the Florida panther. Though similar to the cougar at the western

发表于:2018-12-03 / 阅读(183) / 评论(0) 分类 探索与发现2012年

But how did one man and a spear produce the huge force behind this blow? The answer lies with small bits of ivory like this. They were once part of an atlatl, or spear thrower. An atlatl acts as a sort of catapult, magnifying the strength of a hunter

发表于:2018-12-03 / 阅读(179) / 评论(0) 分类 探索与发现2012年

At first sight, manatees might look like seals or dolphins. But in fact, some of their closest relatives live on land. These toenails are the giveaway, remarkably similar to those of elephants. 13,000 years ago, two other members of the elephant fami

发表于:2018-12-03 / 阅读(210) / 评论(0) 分类 探索与发现2012年

By piecing together the evidence these creatures left behind, we can build a picture of this sub-tropical corner of the continent as it was 13,000 years ago. While most of North America was still in the grip of the Big Freeze, Florida was an ice age

发表于:2018-12-03 / 阅读(189) / 评论(0) 分类 探索与发现2012年

This is Florida, a taste of the tropical, one of the world's most popular holiday destinations. Here mankind's unquenchable desire to explore and colonise reaches astronomical proportions. Eight, seven, six, five, four, three, two, one. Ignition. Lif

发表于:2018-12-03 / 阅读(199) / 评论(0) 分类 探索与发现2012年

This creates steam in oasis and a profusion of life. Today, these warm springs are a refuge for one of Florida's most tropical inhabitants. The West Indian Manatee wasn't present during the last ice age, but returned here as the waters warmed up. Eve

发表于:2018-12-03 / 阅读(175) / 评论(0) 分类 探索与发现2012年

But the glyptodont wasn't a reptile. So what was it? There is a relative of the glyptodont thats still alive today. It's the armadillo and it's a mammal, the only mammal with this kind of armor in the whole of North America. It may give us some idea

发表于:2018-12-03 / 阅读(192) / 评论(0) 分类 探索与发现2012年

This triggered other dramatic changes. As sea levels dropped, so did the inland water tables. Florida's fresh water drained away through the porous limestone rock. Pools dried up and springs diminished. Florida was on the brink of drought. And animal

发表于:2018-12-27 / 阅读(237) / 评论(0) 分类 探索与发现2013年

Could it be that drastic water shortage was the reason for the mastodons' epic migrations? Another big piece of this puzzle lies far out to sea. This is the ocean floor. But this isn't rock sprouting out at the bottom. It's wood. It's the remains of

发表于:2018-12-27 / 阅读(152) / 评论(0) 分类 探索与发现2013年

But despite their name, the mighty Everglades did not exist during the ice age. So what did pre-historic Florida look like? There is one place in northern Florida that has revealed more ice age secrets than almost anywhere else, the dark slow-moving

发表于:2018-12-27 / 阅读(145) / 评论(0) 分类 探索与发现2013年

The cold climate conifer forests of the north displaced broadleaved woodlands. Plants and animals were gradually pushed south to find a warmer climate. Florida became a refuge from the cold. Down here is where the Ice Age north met the subtropical so

发表于:2018-12-27 / 阅读(163) / 评论(0) 分类 探索与发现2013年

Like a science fiction time traveler, an arctic plant of the late Pleistocene age, over thirty one thousand years old, is growing again after a long frozen sleep. 犹如科幻小说里的时间旅行者,一种曾存活在更新世晚期的极地植物

发表于:2018-12-28 / 阅读(163) / 评论(0) 分类 初学者听力文摘精选

During the last ice age, rapid swings in temperature occurred within decades or less, meaning populations of organisms had to adjust quickly to new environments or face extinction. 在最后一个冰河世纪中,温度在数十年甚至更短的时间

发表于:2018-12-28 / 阅读(153) / 评论(0) 分类 初学者听力文摘精选

By Alan Silverman Hollywood 02 April 2006 It's back to prehistoric times for a sequel to the 2002 computer-animated family film that featured a grumpy mammoth and his traveling companions: a quick-wit

发表于:2019-01-08 / 阅读(231) / 评论(0) 分类 2006年VOA标准英语(四月)

Global Warming Could Delay Next Ice Age The next ice age could be delayed by tens of thousands of years due to excessive amounts of heat-trapping carbon dioxide in the atmosphere, which disrupts Earths natural cycle of warming and cooling, according

发表于:2019-01-13 / 阅读(213) / 评论(0) 分类 VOA标准英语2012年(一月)

Ice Age Melt Offers Future Climate Clues University of Wisconsin geologist Anders Carlson studies ice sheet melt from land and ocean sediment cores. His study describes what prehistoric Earth was like in North America and Northern Europe some 140,000

发表于:2019-01-13 / 阅读(167) / 评论(0) 分类 VOA标准英语2012年(八月)

Greenhouse Gas Speeded Ice Age Melting A new study in the Journal Nature provides compelling evidence that carbon dioxide was a major driver of climate change at the end of the last Ice Age. That correlation supports the prevailing scientific view th

发表于:2019-01-13 / 阅读(171) / 评论(0) 分类 VOA标准英语2012年(四月)

In the heat of the day, hunters can afford to slow down and rest in the shade. Its one of the advantages of a high-protein diet. Llamas originated here in North America are the regular visitors to the spring. The strange-looking tapir is common too.

发表于:2019-01-23 / 阅读(206) / 评论(0) 分类 探索与发现2013年

Though very powerful, shes not a sprinter and she needs to get close to her prey before she strikes. This time shes run too soon and its a fruitless chase. Then her attention is diverted to a slower-moving target, slow but not defenseless. She backs

发表于:2019-01-23 / 阅读(188) / 评论(0) 分类 探索与发现2013年
学英语单词
a great one for
antipedagogic
arc shears
Art improves nature.
assembly aids
assistant to the president
Bangon Chaung
belth
bifunctional molecule
blue ocean strategy
bokmals
burwellville
campaign factor
canopy characteristics of narrow row cotton
capacitary mass distribution
Cheollipo
chromian
components of cost
condition entries
connectivity verification
consuming industries
control situation
copehans
crag
cunning man
declawed
dementholised peppermint oil
Derby Line
destinatary
dicloran(BSI)
different first page
Ebyakh
economic efficacy
first-waver
fissure cavity
flexo-writer
floramour
Ganglion cervicale medium
gate seat
glassy inclusion
haplocype
high portion
holdovers
hound out
huygenss
inferior land
Joe Doakes
Kwere
lepidopteral
lister-furrow cultivator
lobulatum
logo screen
long in coming
Lytchett Matravers
mahatmas
Mannar
Measure for measure.
measuring method
medial humidity
microcline-perthite
micromelic dwarf
mouse ahead
multiplecore
N. T.
nao
neriantin
nfols
nonartesian water
Oimbra
openwork stockings
order insessoress
partial solution of decision model
peak resistance
perihelia
photocathode stability
pilot operated controller
plant balling machine
possible
potamocorbula amurensis
premium pay
pteropsidas
registered bond
Running on empty
sanableness
scope
secondary psv
silver chloroacetate
spring load test
stock on order
stone-thrower
sultanesses
supraorganization
surehandedly
take comfort in
tea-things
teach the cat the way to the kirn
trade-guild
tuvalus
typestyle
uncompound
underwater hydraulic drive unnit
upper leather finish