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发表于:2018-11-29 / 阅读(253) / 评论(0) 分类 英语魔法游戏

I am standing at the North Pole, the very top of the earth. Up here, it's easy to see why the Polar Regions are so cold. The sun never rises high enough in the sky to warm my back. And those rays that do strike the surface are mostly reflected back f

发表于:2018-12-03 / 阅读(72) / 评论(0) 分类 自然百科2011年

Over one third of our planet is frozen, and yet the icy worlds of the Arctic and Antarctic are as alien to most of us as the surface of another planet. They are places of superlatives, from ice caps that hold nearly 80% of our planet's fresh water to

发表于:2018-12-03 / 阅读(67) / 评论(0) 分类 自然百科2011年

[全屏观看] 点击右键- 另存为 可保存这个Flash影片 作品简介 : 操作方法:首先点游戏下方的放大按钮,开始按X+C键开始游戏,X键攻击,方向键控制女超人的移动。 游戏说明:地球又一次受到

发表于:2018-12-12 / 阅读(121) / 评论(0) 分类 英语魔法游戏

It's time for the couple to go their separate ways. She will give birth to his cubs alone in nine months time. And he may never see her again. He returns to the frozen ocean, no doubt relieved to resume his solitary ways. And just in time, the ice be

发表于:2018-12-26 / 阅读(42) / 评论(0) 分类 自然百科2012年

A colossal iceberg is born. This single block of ice, many hundreds of meters across would dwarf the biggest of mankind buildings. Every year, tens of thousands of icebergs are spawned by Greenland's glaciers, and their number is steadily increasing

发表于:2018-12-26 / 阅读(50) / 评论(0) 分类 自然百科2012年

This, Jakobshavn Isbrae, is the fastest flowing glacier on our planet, moving as much as 14 meters a day. As it advances, it destroys everything in its path, even cutting its way through Greenland's great mountain ranges on its drive downwards toward

发表于:2018-12-26 / 阅读(55) / 评论(0) 分类 自然百科2012年

During its magnetic cycle, the Sun undergoes periodic changes in activity. Every 11 years, it enters solar maximum. This 11 years cycle of solar activity has peaks where theres lots of solar storms. And right now where the sun is taking a little napp

发表于:2019-01-22 / 阅读(104) / 评论(0) 分类 自然百科2011年

Six years later, they come to believe these light flashes are the results of high energy, heavy cosmic rays penetrating the spacecraft and the crew members' eyes. These/ protons or electrons, just very, very high energy, ripped / part of atoms, sprin

发表于:2019-01-22 / 阅读(80) / 评论(0) 分类 自然百科2011年

By analyzing thousands of lava samples, geophysicists discover/ that the Earth's magnetic field has reversed over 18,000 times in the last 20 million years. On either side of these reversals is a long period of dramatically reduced field strength. Du

发表于:2019-01-22 / 阅读(63) / 评论(0) 分类 自然百科2011年

If we could flip a switch and just turn off the Earth's magnetic field, it will take about 15,000 years to disappear, based on the rate of decay of the field that we've seen over the last 150 years. It's currently decaying at a rate that would see an

发表于:2019-01-22 / 阅读(63) / 评论(0) 分类 自然百科2011年

In polar regions where the magnetic field is / weakest, auroras glow in the sky. These dazzling displays of colored lights form when solar particles slam into gases in our atmosphere causing them to glow. The stronger the solar wind, the more dramati

发表于:2019-01-22 / 阅读(75) / 评论(0) 分类 自然百科2011年

Scientists believe that the South Atlantic Anomaly, is a sign of a global decline in the magnetic field. Evidence of this comes from a surprising source. Dr. Mimi Hill uses pottery to uncover the secrets of earth's magnetic past. Ancient pots tell us

发表于:2019-01-22 / 阅读(67) / 评论(0) 分类 自然百科2011年

Easily confused by this idea, there has a big thawed iron inner core, so that I think it's just the bar magnet, just permanent magnet frozen in nad, and that's where causes all the magnetic field. But it's too hot inside the Earth, that can't happen

发表于:2019-01-22 / 阅读(68) / 评论(0) 分类 自然百科2011年

As the vast sphere reaches / maximum speed, something incredible happens. Huge lines of magnetism arc in and out of the model core. Well, we can't see the magnetic field coming out of the experiment, we can measure them, we can put many different mag

发表于:2019-01-22 / 阅读(72) / 评论(0) 分类 自然百科2011年

Larry Newitt from the Geological Survey of Canada charts the movement of the magnetic North Pole as it wanders the icy reaches of northern Canada. To determine where the magnetic pole / is, we can't rely on one single observation. What I try to do is

发表于:2019-01-22 / 阅读(72) / 评论(0) 分类 自然百科2011年

The relative of the woodlouse is the size of dinner plate. And this so- called sea spider has legs that expand half a meter. Now it's explorer's own revealing other worlds that lie hidden beneath the ice on land. These smoking tars are the gateway to

发表于:2019-01-22 / 阅读(89) / 评论(0) 分类 自然百科2012年

The rule is what goes up must come down, but the trouble is nobody knows exactly where the six-ton NASA satellite will crash land. This white blob is the UARS probe as it spins out of control during its descent, the footage was taken by an astronomer

发表于:2019-02-03 / 阅读(63) / 评论(0) 分类 英伦广角

They were travelling on foot and their first sight of this mountains must have been daunting indeed. In front of them stretched one of the world's longest ranges, spanning two thousand miles from one side of the continent to the other. The winds uphi

发表于:2019-02-15 / 阅读(135) / 评论(0) 分类 自然百科2012年

Youve got these beautiful clear glass-like pillars and right next to it, its really delicate. Look at in them, filament is there. As the cave team explore deeper, each chamber reveals ice crystals more strange and spectacular than the last. No one on

发表于:2019-02-15 / 阅读(130) / 评论(0) 分类 自然百科2012年