Is a massive volume of structured and unsteuctured data so large it is difficult to proces

A．colored sculptures

B．murals

C．a massive volume of manuscripts, documents and books

D．temples

A、 Data Processing system

B、 Big Data

C、 Data warehouse

D、 DBMS

Passage V

An astronomy class is given the following facts about stellar evolution.

1. A star’s evolution can be divided into 3 stages: premain sequence (pre-MS), main sequence (MS), and post-main sequence (post-MS).

2. Gravity causes part of a cloud of gas and dust to collapse and heat up, creating a pre-MS star. The star’s hot dust and gas emit its energy.

3. A pre-MS star becomes an MS star when the star produces the majority of its energy by fusing hydrogen nuclei (protons) at its center to make helium nuclei.

4. An MS star becomes a post-MS star when the star expands in volume and produces the majority of its energy by fusing hydrogen to make helium in a shell surrounding its center.

5. The more massive a star, the more rapidly the star passes through each of the 3 stages of its evolution.Two students discuss the evolution of the Algol system—Algol A, a 3.6-solar-mass MS star; Algol B, a 0.8-solar-mass post-MS star; and Algol C, a 1.7-solar-mass MS star. (One solar mass = the Sun’s mass.) The 3 stars orbit a mutual center of mass, with Algol A and Algol B much closer to each other and to the center of mass than to Algol C.

Student 1

The 3 stars of the Algol system formed at the same time from the same cloud of gas and dust. Algol B, originally the most massive of the 3 stars, became a post-MS star and expanded in volume while Algol A remained an MS star. Because the matter in the outer parts of Algol B was more strongly attracted to Algol A than to the matter in the inner parts of Algol B, this matter flowed from Algol B to Algol A, and, over time, Algol A became more massive than Algol B.

Student 2

Algol B was not part of the original Algol system (Algol A and Algol C). Algol B and the original Algol system formed in different clouds of gas and dust at different times and moved in 2 different but intersecting orbits around the center of the galaxy. During a particular orbit,Algol B encountered the original Algol system at the intersection of the 2 orbits and became part of the Algol system.Algol B became a post-MS star while Algol A and Algol C remained MS stars. Algol B never lost mass to Algol A. Algol B was always less massive than Algol A.

Based on Student 2’s discussion, Algol B is part of the present Algol system because of which of the following forces exerted on Algol B by the original Algol system？

A.Electric force

B.Magnetic force

C.Gravitational force

D.Nuclear force

Task 2

Directions: This task is the same as Task 1. The 5 questions or unfinished statements are numbered 41 through 45.

Until recently the opportunities for criminal activities on the Internet have been low. However, the volume of business done on the Internet is growing rapidly such as ordering books and other products and making money transactions. All this is creating temptations for hackers.

Hackers are often young people who are interested in computers. They use them to move quietly to the Internet, looking for ways to break into computer's systems run by banks, telephone companies and even government departments. They look for examples of credit cards and try to steal the numbers.

Hackers rarely admit to a successful break-in. The first indication of a hacking may be when a customer discovers a wrong money transaction on a credit card account. It is harder to check on somebody misusing an online connection unless there is a massive download of information which would call the attention of the consumer.

The main idea of the first paragraph is that______.

A．the opportunities for criminal activities on the Internet have been low

B．the opportunities for criminal activities on the Internet are low

C．there are more opportunities for criminal activities on the Internet

D．people should not make money transactions on the Internet

Until recently the opportunities for criminal activities on the Internet have been low. However， the volume of business done on the Internet is growing rapidly，as people order books and other products and make money transactions. All this is creating temptations for hackers(黑客).

Hackers are often young people who are interested in computers. They use them to move quietly to the Internet，looking for ways to break into computers systems run by banks，telephone companies and even Government departments. They look for examples of credit cards and try to steal the numbers.

Hackers rarely admit to a successful break-in. The first indication of a hacking may be when a customer discovers a wrong money transaction on a credit card account. It is harder to check on somebody misusing an online connection unless there is a massive down load of information which would call the attention of the consumer.

The main idea of the first paragraph is that ______.

A. the opportunities for criminal activities on the Internet have been low

B. the opportunities for criminal activities on the Internet are low

C. there are more opportunities for criminal activities on the Internet

D. people should not make money transactions on the Internet

The word "temptations" in the first paragraph is closest in meaning to ______.

A. interests

B. attractions

C. benefits

D. profits

In the passage， it's said that hackers may attack the Internet system of all the following institutions except _____.

A. banks

B. telephone companies

C. universities

D. government departments

Which of the following is not the reason for a hacking being found？

A. The customer found something wrong with his account.

B. There was a huge amount of information being downloaded.

C. There was a wrong money transaction.

D. The hacker proudly admitted his successful break-in.

In the last sentence of the paragraph， "somebody" refers to a______.

A. customer

B. card user

C. hacker

D. bank clerk

ual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the U.S. still have levels of carbon monoxide, particulate matter, and ozone that exceed legally established limits. There is a growing realization that the only effective way to achieve further reduction in vehicle emissions—short of a massive shift away from the private automobile—is to replace conventional diesel fuel and gasoline with cleaner-burning fuel such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.

All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds, and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds, involves a more complex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have a set of heavy fuel tanks—a serious liability in terms of performance and fuel efficiency—and liquefied petroleum gas faces fundamental limits on supply.

Ethanol and methanol, on the other hand, have important advantages over other carbon based alternative fuels, they have a higher energy content per volume and would require minimal changes in the existing network for distributing motor fuel. Ethanol is commonly used as a gasoline supplement, but it is currently about twice as expensive as methanol, the low price of which is one of its attractive features. Methanol's most attractive feature, however, is that it can reduce by about 90 percent the vehicle emissions that form. ozone, the most serious urban air pollutant.

Like any alternative fuel, methanol has its critics. Yet much of the criticism is based on the use of "gasoline alone" vehicles that do not incorporate even the simplest design improvements that are made possible with the use of methanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do, other things being equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than "gasoline alone" vehicles fueled with methanol, they would need comparatively less fuel. Vehicles incorporating only the simplest of the engine improvements that methanol makes feasible would still contribute to an immediate lessening of urban air pollution.

The author is primarily concerned with ______.

A．countering a flawed argument that dismisses a possible solution to a problem

B．reconciling contradictory points of view about the nature of a problem

C．identifying the strengths of possible solutions to a problem

D．discussing a problem and arguing in favor of one solution to it

40 years than previously thought due to climate change, Australian and US climate researchers reported Wednesday．Higher ocean temperatures expand the volume of water, contributing to a rise in sea levels that is covering small island nations and threatening to destroy the low-lying, densely-populated low regions around the globe. The study, published in the British journal Nature, adds to a growing scientific chorus of warnings about the pace and consequences rising oceans．It also serves as a corrective to a massive report issued last year by the Nobel-winning UN Intergovernmental Panel on Climate Change (IPCC), according to the authors. Rising sea levels are driven by two things: the thermal expansion of sea water, and additional water from melting sources of ice．Both processes are caused by global warming．The ice sheet that sits atop Greenland, for example, contains enough water to raise world ocean levels by seven meters, which would bury sea-level cities from Dhaka to Shanghai. Trying to figure out how much each of these factors contributes to rising sea levels is critically important to understanding climate change, and forecasting future temperature rises, scientists say．But up to now, there has been a puzzling gap between the projections of computer-based climate models, and the observations of scientists gathering data from the oceans. The new study, led by Catia Domingues of the Centre for Australian Weather and Climate Research, is the first to reunite the models with observed data．Using new techniques to assess ocean temperatures to a depth of 700 meters from 1961 to 2003, it shows that thermal warming contributed to a 0.53 millimeter-per-year rise in sea levels rather than the 0.32 mm rise reported by the IPCC. What happens when the ocean's temperature rises？ A．It causes sea levels to rise. B．It causes sea levels to decrease. C．It causes sea levels to remain unchanged． D．It causes sea flood all over the globe.

根据以下材料，回答题

Older Volcanic Eruptions

Volcanoes were more destructive in ancient history， not because they were bigger， but because the carbon dioxide they released wiped out life with greater ease.

Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals， but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise， the older the massive volcanic eruptions were， the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava that they produced. He found that for size， older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.

The Permian extinction， for example， which happened 250 million years ago， is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatones of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera at the time， and it took 5 million years for the planet to recover. Yet 60 million years ago， there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousands of years. "The most recent ones hardly have an effect at all，" Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago， because many scientists believe it was primarily caused by the impact of an asteroid. He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.

Vincent Courtillot， director of the Paris Geophysical Institute in France， says that Wignall"s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced， and that lava volume may not necessarily correspond to carbon dioxide emissions.

Why did older volcanic eruptions do more damage than more recent ones？ 查看材料

A.Because they killed off life more easily.

B.Because they were brighter.

C.Because they were larger.

D.Because they were hotter.

al motor vehicles, the number of such vehicles has been steadily increasing. Consequently more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone (generated by photochemical reactions with hydrocarbons from vehicle exhaust) that exceed legally established limits. There is a growing realization that the only effective way to achieve further reductions in vehicle emissions—short of a massive shift away from the private automobile—is to replace conventional diesel fuel and gasoline with cleaner-burning fuels such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.

All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn mom cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds, and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds, involves a more complex series of reaction. These reactions increase the probability of incomplete combustion and are more likely to release un-combusted and photo-chemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have a set of heavy fuel tanks—a serious liability in terms of performance and fuel efficiency-and liquefied petroleum gas faces fundamental limits in supply.

Ethanol and methanol, on the other hand, have important advantages over other carbon based alternative fuels: they have a higher energy content per volume and would require minimal changes in the existing network for distributing motor fuel. Ethanol is commonly used as a gasoline supplement, but k is currently about twice as expensive as methanol, the low cost of which is one of its attractive features. Methanol's most attractive feature, however, is that it can reduce by about 90 percent the vehicle emissions that form. ozone, the most serious urban air pollutant.

Like any alternative fuel, methanal has its critics. Yet much of the criticism is based on the use of "gasoline done" vehicles that do not incorporate even the simplest design improvements that are made possible with the use of methanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do; other things being equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than "gasoline clone" vehicles fueled with methanol, they would need comparatively less fuel Vehicles incorporating only the simplest of the engine improvements that methanol makes feasible would still contribute to an immediate lessening of urban air pollution.

The author of the passage is primarily concerned with______.

A．countering a flawed argument that dismisses a possible solution to problem

B．reconciling contradictory points of view about the nature of a problem

C．identifying the strengths of possible solutions to a problem

D．discussing a problem and arguing in favor of one solution to it