单词：tangential polar coordinate
单词：tangential polar coordinate 相关文章
A new study has found that the Arctic's iconic polar bears are finding it harder to hunt for food due to melting sea ice caused by climate change, putting the species at a growing risk of extinction. Researchers from the United States Geological Surv
2018CRI中国国际广播电台
This is Scientific Americans 60-Second Science, Im Cynthia Graber. This will just take a minute. Not too long ago, scientists had to hoof it to the library to review the literature. And they had to flip through a card catalog to find that dusty old v
Scientific American(七)月
When the Arctic Ocean freezes over in the autumn, polar bears set off in search of their favorite meals: fatty ringed seals and bearded seals. By the summer, the sea ice begins to melt and break apart. Deprived of access to the tasty seals, polar bea
2016年Scientific American(十)月
Climate Change Fires Up Polar Bear Treadmill 气候变化害苦了北极熊 Polar Bears spend most of their time roaming the sea ice in search of seals. And seals spend most of their time underneath that ice, avoiding the top predator. But climate ch
2017年Scientific American(八)月
Seventy-nine degrees north latitude is near the top, at the cold edge of the world. In the winter, when temperatures plunge below freezing, there is complete darkness at noon. During summer, the sun shines at midnight, there is no place to hide. Dang
国家地理2007年
She worries a lot. She worries about polar bears. They are big, white bears. They live in the north. They need snow. They need ice. They need cold weather. There is too much pollution. Pollution heats up the Earth. Heat melts the ice. The ice is the
儿童英语小故事
By Paul Sisco Washington 16 May 2008 The United States Government, Wednesday [May 14] officially added polar bears to the list of threatened animals under the Endangered Species Act. Bush administration scientists decided the species is at risk of be
VOA标准英语2008年（五月）
New Movie Boosts Campaign to Save Polar Bears Polar bears are in trouble. Scientists say only 20,000 remain, and their long term survival could be at risk. The new IMAX movie, To the Arctic, is narrated by actress Meryl Streep. The movie tells the st
VOA标准英语2012年(五月)
Polar Scientist Charts Melting Caused by Climate Change Michael Gooseff follows water to the end of the earth. The Pennsylvania State University hydrologist works in remote regions of the Arctic and Antarctic, where ice and frozen ground are thawing.
VOA标准英语2011年(八月)
BBC Learning English Weekender Polar Explorer Amber: Hello, I'm Amber, and youre listening to bbclearningenglish.com. In Weekender today, we listen to an interview with explorer, Rosie Stancer. In March, Rosie sets off on her latest expedition walki
Weekender
By Kane Farabaugh New York City 01 August 2007 During the Cold War, Greenland was a strategic location for the United States military to track and detect Soviet aircraft and ballistic missiles. The military established radar and tracking sites throug
2007年VOA标准英语（八月）
STOCKHOLM, May 8 (Xinhua) -- The 2012 Swedish Polar Music Prize was awarded to the American singer-songwriter Paul Simon and the Chinese American cellist Yo-Yo Ma, the prize committee said in a statement on Tuesday. For five decades, Paul Simon has b
英语新闻
Voice 1 Thank you for joining us for todays Spotlight. Im Rebekah Schipper. Voice 2 And Im Joshua Leo. Spotlight uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live. Voice 1 Sib
环球英语 Spotlight
The dogsled skimmed silently over the frozentundra. The seal hunter ran alongside it. Sometimeshe cracked his whip against the ice. The snowdrifts looked like giant white sculptures asthe sun slipped behind the frozen hills. Then a fullorange moon ro
汪培珽儿童英文分级书单《神奇树屋》
The dogs were barking wildly at two smallcreatures playing in the moonlight. Polar bear babies! cried Annie. One roly-poly cub leaped onto the other. Then theyboth rolled through the snow. Hi, little bears! Annie called. The cubs jumped up and shook
汪培珽儿童英文分级书单《神奇树屋》
The cubs whimpered louder. They want to go to her, but they're afraid of theice, whispered Jack. Annie petted the cubs. Don't be afraid, she told them. You'll get back toyour mother.The big polar bear growled. She paced back andforth, sniffing the ai
汪培珽儿童英文分级书单《神奇树屋》
Jack, you can get up now, said Annie. Jack opened his eyes. Annie was standing over him. She still had her mask on. We're on safe ground, she said. Jack felt as if he'd been dreaming. He lookedaround. They had reached the tundra at the edge ofthe fro
汪培珽儿童英文分级书单《神奇树屋》
Now only the moon shone on the snow. Jack looked around for the polar bear. She was gone. Where'd she go? asked Annie. I don't know, said Jack. He looked over thetundra. There was no sign of the giant bear or hercubs. Maybe she's not interested in sc
汪培珽儿童英文分级书单《神奇树屋》
BEIJING, June 21 (Xinhua) -- China will launch a new icebreaker for use during an upcoming 2013 polar expedition, a senior oceanic official said on Tuesday. Both the new icebreaker and Xuelong (Snow Dragon), an icebreaker that operated in Antarctica,
英语新闻
Voice 1 Hello, Im Marina Santee. Voice 2 And Im Ruby Jones. Welcome to Spotlight. This programme uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live. Voice 1 A tall man stands s
环球英语 Spotlight