光面单缝孢群〔孢粉〕

A hundred years ago, there are one and a half billion people on earth. Now, over six billion crowd our fragile planet. But even so, there are still places barely touched by humanity. This series will take you to the last wildernesses and show you the

发表于:2018-12-03 / 阅读(73) / 评论(0) 分类 探索与发现2012年

Doug Levine | Washington 29 March 2010 January 23 marked the 100th birthday of the influential jazz guitarist and composer Django Reinhardt. Today, more than 50 years after his death, musicians are still paying tribute to the man who elevated the gui

发表于:2018-12-16 / 阅读(89) / 评论(0) 分类 VOA标准英语2010年(三月)

The penguins stay when all other creatures have fled because each guards a treasurea single egg rested on the top of its feet and kept warm beneath the downy bulge of its stomach. There is no food and no water for them. And they will not see the sun

发表于:2018-12-27 / 阅读(77) / 评论(0) 分类 探索与发现2012年

2011年秋季,Peter Norvig和Sebastian Thrun在斯坦福大学开办了一个由175在校学生出席的的人工智能课程这同时还有超过十万的学生通过互动直播来观看这个网络课程。他将与我们分享从这个环球教室

发表于:2019-01-05 / 阅读(80) / 评论(0) 分类 TED公开课:群体的力量

欣赏独具创意的英语广告!边听边看边学,品味世界名牌的风范,从细微之处感受英美社会的文化。

发表于:2019-01-05 / 阅读(133) / 评论(0) 分类 广告大餐

They are constantly on the move. New-born calves have to be up and running the day they are born. But the vast herds do not travel alone. Wolves. Packs of them, eight to ten strong, shadow the migration. And they are hungry. Its the newly born calves

发表于:2019-01-23 / 阅读(83) / 评论(0) 分类 探索与发现2012年

But they are hungry and eager to reach their mother whos delayed feeding them on this special day. Now she lures them with the promise of milk, the only food the cubs have known since they were born, deaf and blind beneath the snow some two months ag

发表于:2019-01-23 / 阅读(90) / 评论(0) 分类 探索与发现2012年

Day 10. And the mother has let her cubs a mile from the den. Its time to put them to the test. Theyve grown enormously in confidence, but they dont have their mothers sense of urgency. At last it seems that they are ready for their journey. And they

发表于:2019-01-23 / 阅读(77) / 评论(0) 分类 探索与发现2012年

Midsummer on the tundra and the sun does not set. At these altitudes, the suns rays are glancing and not enough of their energy reaches the ground to enable trees to grow. Youll need to travel five hundred miles south from here before that is possibl

发表于:2019-01-23 / 阅读(78) / 评论(0) 分类 探索与发现2012年

As we travel south, so the suns influence grows stronger. And at 50 degrees of latitude, a radical transformation begins. Summers here are long enough for broadleaf trees to replace conifers. Broadleaves are easier to eat and digest, so now animals c

发表于:2019-01-23 / 阅读(97) / 评论(0) 分类 探索与发现2012年

The advance of the seasons brings constant change. As the suns influence diminishes in the north, so the deciduous forests of America begin to shut down, losing their leaves in preparation for the dark, cold months ahead. One season hands over to ano

发表于:2019-01-23 / 阅读(72) / 评论(0) 分类 探索与发现2012年

The character of the forest changes as we descend, becoming ever darker and damper, favoring different kinds of animals and plants. Less than two percent of the sunlight reaches the floor. But even here there is extraordinary variety. In the Great Is

发表于:2019-01-23 / 阅读(67) / 评论(0) 分类 探索与发现2012年

The female retires to consider her verdict. Its hard not to feel deflated when even your best isnt good enough. The sun influences the lives in the ocean just as it does on land. Its richest parts are those where waves and currents bring fertilizing

发表于:2019-01-23 / 阅读(103) / 评论(0) 分类 探索与发现2012年

The strike of a great white shark lasts a mere second. Slowing it down forty times reveals the technique and immense strength of this massive predator. If surprise fails, there will be a chase. The shark is faster on a straight course, but it cant tu

发表于:2019-01-23 / 阅读(187) / 评论(0) 分类 探索与发现2012年

The sun beating down on tropical waters powers the weather systems of the globe. Moisture evaporates from the warming ocean and rises to create great storms. The winds generated out at sea sweep inland across the continents. As they travel across the

发表于:2019-01-23 / 阅读(68) / 评论(0) 分类 探索与发现2012年

Deer are frequent casulties of the harsh winter. And these leopards are not above scavenging from a corpse. African leopards could never survive here. But the Russian cats have thick fur to shied them from the cold. There are only 40 Amur leopards le

发表于:2019-01-23 / 阅读(101) / 评论(0) 分类 探索与发现2012年

Their secret is teamwork. Impala are their favourite prey. They start to hunt and the pack splits up. An aerial viewpoint gives a new insight into their strategy. As the dogs approach their prey, they peel off to take up separate positions around the

发表于:2019-01-23 / 阅读(63) / 评论(0) 分类 探索与发现2012年

The dogs know their prey must come out or drown. Now its a waiting game. The rest of the pack are calling. Theyve made a kill in the forest and this is an invitation to join in the meal. The impala is in luck. A pack this size kills once a day and ev

发表于:2019-01-23 / 阅读(74) / 评论(0) 分类 探索与发现2012年

All across southern Africa, all animals are journeying for the same reason. Buffalo join the great track. Nowhere else on Earth are so many animals on the move for the same urgent purpose. They are all heading for the swamps of the Okavango, a vast i

发表于:2019-01-23 / 阅读(76) / 评论(0) 分类 探索与发现2012年

At the peak of the dry season in the Kalahari, water arrives in the Okavango. It fell as rain a thousand miles away in the highlands of Angola and has taken nearly five months to reach here. The water drives out insects from the parched ground which

发表于:2019-01-23 / 阅读(66) / 评论(0) 分类 探索与发现2012年
学英语单词
ac/ac converter
all-giver
amuse oneself
anaphylodiagnosis
and-god
anthostomella taiwanensis
antimonous acid
area velocity
arm-chest-height
audrina
autonomin
axle journal(axle-neck)
be rolling in
bearing data
biocremations
birth-rates
block stone arch bridge
bond floatation
bound in/on/to
Breitenwang
cable mechanics
central american countries
chip on chip
cosine roll off characteristic
crossovers
D'Amato's sign
D. H. L.
diloscope
dizirconyl nitrate
educationalize
Etretin
experience-near
extruser
F. & C. C.
file create and maintenance
fin cutting
float product
forsung
good-neighbourly
governments-to-governments
granite chippings
gravity stamp mill
grease gun nipple
heap element
heat management
high-speed telescope
homogeneous fleece
hurry it up
ibam
introitus vaginae
ioniser
itshay
keyboard function
lampkin
librium (chlordiazepoxide)
Luc Hanh
mid-ocean rise
Moentsa
mollisacacidin
munchens
New England Confederation
nonrelatives
nook or cranny
obrode
oceanview
Phellopteras Httoralis Benth.
pin type cage
playfriends
practicalism education
precipitability index
pressure in air receiver
pressure lubricator
protector glove
pseudo-colilid
quality scale
reliability control
residual mismatch
resource pool
resynchs
ring groove side
scal-of-two counter
setulae
shut-in
side benefits
side chain motion
silk-tail
six sided nut
spiffed
stable static model
Suchixtepec
supratemporal fossa
terminal area surveillance radar
thumble
tillage control measure
Tintigny
tractus corticotectalis
transaction note
trophi-
underground presses
unnotched type bearing
wing root chord
wired synchronization system