新冰期

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(47) / 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(58) / 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(63) / 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(61) / 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(68) / 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(49) / 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(65) / 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(69) / 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(53) / 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(47) / 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(49) / 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(49) / 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(64) / 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(47) / 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(114) / 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(79) / 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(61) / 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(57) / 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(64) / 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(57) / 评论(0) 分类 探索与发现2013年
学英语单词
abnormal polychromate
aeromagnetic prospecting
aldononitrile
amnihook
angerless
angular error indicator
antiaircraft forces
any old how
arc de triomphe
Atelognathy
axillary lymphatic plexus
aynak
battery glass
blacke saunts
bleached flour
body tappet
build up family fortunes
business profit tax
capoten
categorizing
central principal axis
choice of parent
chronointerfometer
close pair
combine height
common spotted orchids
concentric annulation
contract ship
control pass
cotylosaurs
cursor indicator
deep wing
Degerfors
deiras
dense phase fluidized bed
die dog for someone
dominating set
doojiggers
encoded information type
endoglycanases
Ethiquinium
extensional tectonics
fibr-
Goundi
grate bar bracket
great smoky mts.
ground water chemistry
Harvard formats
hemangioleimyolipoma
henes
hereditary muscular atrophy
hippotigrine
hundred proof
hydrogen-cooled machine
hysterocystocleisis
ihnatko
Ilgner generator set
internal corner
isohygromen
land of cutting tool
laughs off
lime-trees
maddest
marie-france
meringum holochilum copel.
mescomine
multiplication rate
naviform
non integral fuel tank
nyctotyphlosis
O'Beirne's tube
oil-resistant coating
organ of public opinion
paroxysmal hyperthyroidism
pitchier
Pittsburghese
postcoding
preductules
premaxillary palate
principalships
resin pocket
Rimatara
salt pillar
screwin
snowwhite
sorrowing
springing arrangement
Student Nonviolent Coordinating Committee
submergings
tawny frogmouth
temporize with
thio-
traditional values
two-of-a-kind
unconcentrated flow
unpropagatable
vegetable milk
vilmoriniana
wasint
weight-train
xerox copy
zero level economics