Questions 6 through 11.
Listen to part of a lecture in an astronomy class. The professor is talking about the auroras.
W: For centuries, people have told stories to explain the moving lights in the night sky the curtains of greenish–white light with pink fringe. People described these lights as the breath of the Earth, powerful spirits, or angel light. An early twentieth– century explorer wrote about the “bloody red” and “ghostly green” lights. These lights, of course, are the aurora borealis the northern lights and, in the south, the aurora australis. Most of the time they’re greenish-yellow, but sometimes they take colors from violet to red. The auroras can be seen at any time of the year, with the right atmospheric conditions. They’re most often seen near the North and South Poles, during times of maximum solar activity. The closer to the North or South Pole you are, the better you can see the lights.
The auroras occur in the ionosphere. The ionosphere is the layer of the upper atmosphere where high- energy solar radiation strips electrons from oxygen and nitrogen atoms, and leaves them as positively charged ions. The auroras are the result of a complex interaction between the solar wind and the Earth’s magnetic field. Here’s what happens. The sun’s heat charges the particles in the solar wind, a stream of electrically charged subatomic particles that continually emanates from the sun. As the solar wind approaches Earth, it’s deflected by Earth’s magnetic field and diverted north and south toward the magnetic poles. The interaction between the solar wind and the magnetosphere generates beams of
electrons. These electrons collide with atoms and molecules within the ionosphere near Earth’s magnetic poles. The collisions rip apart molecules and excite atoms. Thus, oxygen and nitrogen atoms in the ionosphere become “excited,” or ionized. The auroras happen when these ionized atoms return to their normal state from their excited, energized states. The ions combine with free electrons—as they do so, they emit radiation. Part of this radiation is visible light: the aurora borealis and aurora australis.
M: Uh … it sounds kind of like electricity.
W: Yes, that’s right. The auroras are an electrical
phenomenon. As you know, an electrical generator has two components: a conductor and a magnetic field. To generate electricity, the conductor has to move across the field to produce a force. With the auroras, the conductor is the solar wind carrying a stream of charged particles.
M: So, what happens is, when, uh, when the charged particles reach Earth’s magnetic field, they, uh, move along in the field towards the north and south magnetic poles.
W: Exactly. And then the particles collide with gases in the atmosphere—oxygen and nitrogen and the oxygen and nitrogen atoms get excited. And then, when the particles get de-excited and return to their normal state, they emit the auroras by releasing energy in the form of light. Oxygen releases either dark red or ghostly green. Nitrogen emits rosy pink or magenta. The activity of the auroras varies with the sun’s activity. When the sun is quiet, the auroras can be seen only in a small area. When the sun is active, however, the aurora borealis can be seen across southern Canada and the northern United States.
Questions 12 through 17.
Listen to pan of a lecture in a political science class. The professor is discussing political parties.
Mr At the heart of the system of government called “democracy” is the institution of elections. The electoral system is the basic machinery by which popular government is excrcised. And at the heart of the electoral system are political parties that organize voters and compete for support on issues. Participating in democratic politics means joining or supporting a political party. It means taking sides on central political issues. Political parties are the mechanism for selecting candidates and gaining support at the polls. Parties vary significantly in different countries, but all parties have certain common features. Political parties are voluntary organizations, generally national in scope, made up of people who agree to some degree on public policies. In the United States and Canada, political parties are stable, and each party tends to embrace a wide range of views and interests. The democratic institutions of these countries operate essentially on a two–party system. Why a two-party system? Or, should I say why has the two-party system prevailed in so many democratic states? For one thing, the essence of politics is debate; there must be someone to debate with. A one-party system means one party monopolizes power and talks only to itself. A one- party system can only be totalitarian, and therefore quite distinct from democracy.
W: Isn’t it true that another reason we have two parties is because, uh, because libera) and conservative attitudes are basic human uh. I mean they’re a basic part of our nature. In fact, almost every thing that we think or do seems to come down to having to there being two different ways of seeing the world.
M: That’s an interesting idea. We even have the saying. “There are two sides to every coin.” In every democratic society, there are generally two dominant parties one for each side of the coin. In the United States, it’s the Democrats and the Republicans. In Canada, it’s the Liberals and the Conservatives. In both countries, the two parties are balanced enough so the minority party can become the majority by gaming an additional small share of the votes. The two parties have lasted so long because they have the ability to adjust to changes in events and in public opinion. But in addition to the two major parties, there arc also several smaller parties on the margins of political power. There arc lots of political factions that sometimes compete at elections. Parties are closely associated with various pressure groups, interest groups, lobbies, occupational organizations, and other groups that want to influence the decisions of the state. The purpose of each major party is to capture the legislative and executive organs of the state in order to get the party’s policies accepted. The aim of parties is to win elections. However, winning
an election isn’t the same thing as capturing the power of the state. What really happens is, the state captures the winning party. Why is this? Well, for one thing, the experience of government tends to soften the contrasts of political debate. Government is a responsible business, while politics is a game with teams competing for victory.
W: Excuse me, Dr. Reed, but isn’t it. I mean, then what you’re really saying is, government and politics aren’t the same thing. You said that government is a serious business, but politics is like a game.
M: Right! Politics is a game. In politics, teams and individuals take risks, and there are winners and losers. Competition is the essence of politics. But with government, collaboration and compromise are necessary because the job has got to get done.
So, why do we need political parties? We need parties because, for one reason, the process of policy formation takes place there. Parties maintain research offices and establish connections with press and citizens groups. This is how political parties develop information and thinking on major issues. The major parties retain enough differences so they can appeal to different groups of voters, and so they can offer alternatives to the independent voters who don’t vote purely on the basis of party loyalty. However, the party platforms tend to balance each other in the types of issues they take up. For example, when one party introduces a plan for education reform, the other party generally takes up education as well.
Questions 18 through 22.
Listen to part of a conversation between two students.
W:My linguistics class is really getting good. Today the lecture was about the social aspects of language, like slung and accents, and stud. But the thing that really intrigues me is something called a lingua franca.
W:Yeah. A lingua franca is sort of common language used by people who speak different languages. There are a lot of places in the world where everybody’s first language is different, and the people need to communicate with other groups, so everybody starts using one language for social or commercial relationships. That language that connects them all is a lingua franca.
M:That makes sense kind of a universal business language. Where did the name “lingua franca” come from?
W:From the name of one of the first languages like that. It was like, in the Middle Ages, countries with ports on the Mediterranean needed a common trade language. So a new language sort of evolved. It was basically Italian, mixed with French, Spanish, and other languages. It was called Lingua Franca, which meant “Frankish language.” After that, “lingua franca” came to mean all languages used that way.
So, any language can be a lingua franca if it connects lots of people who speak different languages. Most of the time lingua francas have been trade languages.
M:That means English is a lingua franca because English is an international business language.
W:Yeah. You’re right about that. English is definitely a lingua franca. In East Africa, Swahili is a lingua franca that’s understood in every marketplace. It’s because there are hundreds of tribes in East Africa, and each tribe speaks a different language So most of the people there learn at least some Swahili as a second language.
M:Interesting. And … uh … isn’t there some other language like that… I think it’s called something like “pigeon” … you know, like the birds, like the pigeons that carry messages.
W:It’s not “pigeon” like the birds! It’s a different word—here, let me show you—it has the same pronunciation, but a different spelling. A “pidgin” is a type of language. It’s a simplified language that’s a mixture of two or more languages. It has words from both languages.
M:Oh, yeah. Now I remember. We studied pidgins in anthropology.
W:My professor said there are lots of different pidgins based on English that developed in different parts of the world. It was because people from English¬speaking countries had to communicate with the local people. Pidgins have a simple grammar and vocabulary, so they’re easy to learn.
M:That’s cool. Your class sounds interesting.
W:Yeah, we’re learning some pretty amazing stuff.
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