N: NARRATOR P: PROFESSOR
N: Listen to a talk on glaciers.
P: OK, let me start off by giving you some facts about […………………………]. About […………………………]of the Earth’s land Is covered with glaciers. This actually Isn’t very much compared to the last Ice Age when about a third of the Earth was covered with glaciers. Glaciers store about […………………………] of the Earth’s fresh water, So if all the glacier Ice […………………………], sea levels would probably rise about […………………………]or […………………………]all over the world. Why do I tell you this as though It were fact? Well, glaciers are melting all over the world. And that’s what we’ll be discussing today.
OK, a lot of people perceive glaciers as being […………………………]Icebergs because icebergs break off of glaciers. Actually, a glacier Is a large […………………………]long-lasting river. As snow gets more and more compacted, the glaciers become heavy and deep enough to actually flow. This is why they’re known as rivers of Ice. Now you might think that glaciers are found only In […………………………]and the northern hemisphere close to the Arctic Circle, but there are glaciers on every […………………………], including Australia. Alpine glaciers cover mountain […………………………]and continental glaciers cover large areas of continents. There are, of course, other […………………………]based on size, location, how they’re formed but for now let’s focus on what happens when they mart.
When a glacier is at melting point throughout the year from the base of the glacier to Its […………………………], we call this a temperate glacier. The snow on temperate glaciers repeatedly […………………………]and melts a bit, which makes the ice somewhat […………………………]. The layers of Ice and snow make this granular ice Into a […………………………]type of ice called firm. It continues to […………………………]further compaction until it becomes glacial ice, a blue Ice. Now the layers below the glacial ice become […………………………]under the pressure and this Is what makes glaciers move like a thick […………………………]. During the metting process, the […………………………] flow throughout and beneath the glacier, and this helps It to move. So the upper part of the glacier receives the most amount of snow and is called the accumulation zone. On the opposite end, the foot or terminal part of the glade, Is the part where more ice is lost due to melting … this is called […………………………]. A glacier is cailed healthy If its […………………………]is equal to Its ablation.
How healthy are the Earth’s giaciers today? Uh … not very healthy. The glaciers are undergoing a […………………………]known as glacier retreat … This has been occurring since the […………………………]and Is related to global warming. In the Antarctic, […………………………] of the glaciers have […………………………]In the past 50 years. Temperatures in the a’ea have Increased by as much as […………………………]degrees Centigrade. The same is happening to the Arctic glaciers. Since […………………………], floating glacier ice sheives, which are […………………………]to a land-based glacier, have been retreating an average of […………………………]feet or […………………………] meters. All over the wortd, […………………………]are recording the retreat of glaciers. Grlnnell glacier at Glacier National Park has receded so much that it can almost no longer be seen. Visitors to the Alps can see the […………………………]of the glaciers. Greenland’s huge Ice cap appears to be thinning and flowing more rapidly. The retreat of a glacier Isn’t really a simple phenomenon, though.
What are the results of glacier […………………………]? There’s a new study that […………………………]glacial matt as the leading source of ocean rise. This study, which was conducted by US scientists, seems to […………………………]studies conducted In the past and which concluded that rising […………………………]are causing the oceans to swell. But a careful look at the data In the new study seems to show that glacial retreat is making the oceans rise. How big a threat is this melting … to the planet Earth? Of course, […………………………]areas will be the first to be affected by ocean water rise. The low-lying Pacific Islands could be Inundated. Bangladesh, Florida, the Everglades and Alaska have been suffering effects from sea level rise.
What do scientists foresee as the Impact of continued glacial retreat? Well … some areas depend on water […………………………]from glaciers and If these keep […………………………], there won’t be enough runoff to water the crops and to keep water dams and […………………………]filled. It would be especially terrible for South America, whose lakes are filled by glacier runoff. Glacier runoff In the northern […………………………]is used for hydropower. What eise? Plants and animals that depend on glacler-fea waters may not be able to […………………………]without the water that they have […………………………]to. The ocean currents will be […………………………]by the Increased Inputs from […………………………]. This would have an Impact on the fishing waters that many humans depend on. And how fast are ocean levels rising? Well, as of now we are experiencing a sea level rise of about […………………………] […………………………]and this will Increase another eight Inches within the […………………………] century.
N: Listen to part of a lecture in a history class.
P: Alright, can anyone tell me who […………………………]the printing press?
S: Wasn’t It Gutenberg?
P: Aaaahh, the great Johannes Gutenberg. Well … that is what many of us have been taught, and It Is fair to say that he invented a printing press circa […………………………]. However, was It the first? There’s a good deal of […………………………]out there Indicating that the truth is not so … hmm, cut and dried.
First, let’s get technical […………………………]straight. What exactly is a printing press? I mean, I could track mud onto pieces of paper, and my shoe might be considered a printing press, by a broad definition. […………………………]forms of printing such as signet rings, seals, and […………………………]have been used since […………………………]. Block printing, a process not so different from laying […………………………], actually, is considered the first method of printing In any […………………………]volume. It arose In China sometime from the 4th to the 7th century A.D. Block printing did make an Impact because It produced pages faster than […………………………], but it was Impractical by modern standards because each page’s printing block had to be hand […………………………], Labor-intensive technology. Plus, the […………………………]would not last that long,
The real […………………………]was movable type. Again In China, an alchemist named Pi Sheng is credited with Inventing movable type around the year […………………………]. Ah, however, his technology also had some problems, His type pieces were made of […………………………]and […………………………], so they weren’t […………………………]enough to stand up to long-term use. Later, carved wood v/as used for individual type pieces, but they were no more […………………………]than the old-fashion woodblocks. Still, movable type was a great […………………………], A page of print could be made by arranging existing type pieces. By the end of the 9th century, this printing technology was […………………………]used to reproduce Confucian texts, Buddhist […………………………], and, uh, various academic books, but still the technology was not the […………………………]that it would be in Europe.
OK, some of you may have heard that the Koreans actually Invented the printing press. Again, only partially true. The Korean […………………………]was movable copper type. Invented as early as […………………………], metal type obviously is much more […………………………]than clay or wood. Strangely, though, here too the technology did not have a huge cultural impact. Why? Weil, one reason is that Korea happened to Invent the world’s first practical printing press before It had a, uh, […………………………]alphabet. That particular Invention wouldn’t come until, um, […………………………]. Sure, the Korean […………………………]were using Chinese script, but Chinese has thousands and thousands of characters because It’s not […………………………]. Chinese characters are […………………………], essentially pictures of ideas. Think about it. A printer would have to […………………………]an average of […………………………]characters for a single page of print. You can imagine how labor-intensive printing In Chinese was … even with movable-type technology. Ah … any questions so far?
S: Um, so, are you saying that Gutenberg didn’t invent the printing press?
P: Ah, yes! Our old friend Johannes. Well, yes, again, he did invent a printing press, but did he do It […………………………]of any knowledge of the Aslan advances in the […………………………]centuries? Was he even the first European to put together a press? Weil, this is where things get a bit […………………………].
Let’s first address the question of cultural […………………………]: Did Europe know about Asian print technology? Well, by the 13th century, Marco Polo had visited China. It is almost certain that he and other Silk Road travelers brought back to Europe […………………………] […………………………], money, playing cards, et cetera, et cetera. Europe now had evidence of printing unlike its ovvn woodblock technology. All of a […………………………], movable- type printers began […………………………]up in Italy, Holland, Prague, and Germany, and […………………………]was one of them.
So, who perfected the […………………………]movable-metal- type printing press? Well, credit Is given to a Dutchman, ah, Laurens Janszcon Coster, an Italian, Pamfilo Castaldi, and, of course, the famous German Johannes Gutenberg. Who was the first? History has yet to give us one clear name, but one thing cannot be […………………………]. Gutenberg was the most successful.
A […………………………]set of circumstances […………………………]the European printing press and Gutenberg to success. First and most […………………………], European alphabets are phonetic and have only […………………………]of characters to set in type, as opposed to thousands in Chinese. This fact makes movable-type printing a much better match for Europe. Ah, secondly, Gutenberg […………………………]onto the idea of printing the Bible. Not only was Europe extremely […………………………]compared to Asia, the Protestant Reformation was […………………………]when print technology was taking hold In Europe. As the Latln-basea
Roman Catholic religion was falling out of favor In Germany, native […………………………]was gaining in popularity … uh, especially as the printing press was making […………………………]material cheap and available to a wide, wide […………………………].