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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(122) / 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(127) / 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(138) / 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(138) / 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(141) / 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(127) / 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(127) / 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(141) / 评论(0) 分类 探索与发现2012年

Online Classes May Force Changes at Universities This is pretty amazing, said the University of Virginia's David Evans, teaching an online introduction to Computer Science. Online classes are now taught by many top universities and offer everything f

发表于:2018-12-16 / 阅读(139) / 评论(0) 分类 VOA标准英语2013年(六月)

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(154) / 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(112) / 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(114) / 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(111) / 评论(0) 分类 探索与发现2013年

By Dan Robinson Capitol Hill 18 May 2006 U.S. officials say implementing the Darfur peace agreement requires sustained international attention to Sudan in coming months. A congressional hearing examin

发表于:2019-01-07 / 阅读(189) / 评论(0) 分类 2006年VOA标准英语(五月)

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(182) / 评论(0) 分类 2006年VOA标准英语(四月)

Ocean Floor Reveals Past Climate Changes Time capsule Lamont research professor Maureen Raymo, the director of the Core Repository, slides open a long, narrow drawer from the cabinet. Like thousands of others here, the drawer contains a long, thin cy

发表于:2019-01-13 / 阅读(175) / 评论(0) 分类 VOA标准英语2012年(一月)

Supernatural Romance, Action Attract All Ages In the Houston suburb of Tomball, these women get together frequently to socialize and chat about the books they are reading. Cathy Clark says many of those books - targeted at teens - also attract adult

发表于:2019-01-13 / 阅读(138) / 评论(0) 分类 VOA标准英语2012年(三月)

The Science of Climate Change Climate negotiators are meeting in Durban, South Africa beginning from November 28-December 9 to discuss the planet's changing climate. The first decade of this century was the hottest on record. Polar ice is melting. Gl

发表于:2019-01-13 / 阅读(130) / 评论(0) 分类 VOA标准英语2011年(十一月)

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(136) / 评论(0) 分类 探索与发现2013年

SCIENCE IN THE NEWS - November 12, 2002: Oldest Evidence of Jesus? / Mapping Genes that Cause Disease / 2002 World Health Report VOICE ONE: This is Steve Ember. VOICE TWO: And this is Bob Doughty with

发表于:2019-01-30 / 阅读(184) / 评论(0) 分类 科技之光
学英语单词
actual stress
adzic
alaspinulae
anti-rust property
Antigonus I Monophthalmus
antipasti
apiolic acid
auriculotemporal nerve
automatic sequence controlled computer
axes of maximum moment of inertia
banisht
base of prism in
bohigian
broetje
caducid
Canárias, I.das
car sill
centrifuge reclaiming
CloudStack
cly-
co-financing
cuspate ripple mark
dermathemia
diabetess
difficult to form
disseparable
Drentse Hoofdvaart
dropping mercury cathode
EM (emergency)
EU-5306
evideur
falls into
false social value theory
finite sequence
flydge
fungus
fuselage afterbody
futuro
geomagnetic inclination
gustatorius
hard magnetic material
harpy-bats
hazardous site and spot
high-voltage condenser
hinnom
hydropipers
hypsibarbus pierrei
identity period
inclined sack elevator
ingluvies
instrumental musics
interzooidal
intestinal holding forceps
intrinsically safe
inventory error
IUD
Khadki
local canonical parameter
loooving
lumberg kiln
Lythraceae
maackia chindnsis takeda
magnetic push
major quadrat
mature labour power
maximum output inductance
mirrorstone
monoglucosylated
Morton's Fluid
multifocal
one-dimensionally
outboard course orientation
pay horizon
phutz
prison-issues
Protomyzostomum
pseudoblock
public expenditures on education at current market prices
randonnee
Regio buccalis
regulation of school charges
resident status
resistance box with terminal
scattering loss in optical thin-film
Silene latifolia
slip-band
stagger feed
Surgāna
tasmin
telephone ECG system
text formatting system
toll key
ton-miles
triumphs over
uranium-bearing silicalite
V-R relaxation
valve-type lightning arrestor
vertical rotor
water-trap stomach
wern
wire chase
Zevenaar