2023 年 03 月大学英语六级考试真题（第 1 套）

A)The fog still chills the morning air and the cable cars still climb halfway to the stars. Yet on the ground, the Bay area has changed greatly since singer Tony Bennet left his heart here. Silicon Valley and the tech industry have led the region into a period of unprecedented wealth and innovation. But existing political and land limits have caused an alarming housing crisis and astronomical rise in social and economic difference.

B)While the residents of most cities display pride and support for their home industries, drastic market distortions in the San Francisco Bay Area have created boiling resentment in the region towards the tech industry. A vocal minority is even calling on officials to punish those who are benefitting from the economic and housing boom. If this boom and its consequences are not resolved, a drastic increase in social and economic difference may have a profound impact on the region for generations. A history and analysis of this transformation may hold invaluable insights about the opportunities. Perils of tech cities are currently being cultivated across the US, and indeed around the world.

C)According to a recent study, San Francisco ranks first in California for economic difference. The average income of the top 1% of households in the city averages $3.6 million. This is 44 times the average income of those at the bottom, which stands at $81,094. The top 1% of the San Francisco peninsula's share of total income now extends to 30.8% of the region's income. This was a dramatic jump from 1989, where it stood at 15.8%.

D)The region's economy has been fundamentally transformed by the technology industry springing from Silicon Valley. Policies pushed by Mayor Ed Lee provided tax breaks for tech companies to set up shop along the city's long-neglected Mid-Market area. The city is now home to Twitter, Uber, Airbnb, Pinterest, Dropbox and others. In short, the Bay Area has become a global magnet for those with specialized skills, which has in turn helped fuel economic enthusiasm, and this economic growth has reduced unemployment to 3.4%, an admirable feat.

E)In spite of all that, the strength of the recent job growth, combined with policies that have traditionally limited housing development in the city and throughout the peninsula, did not help ease the affordability crisis. In 2015 alone, the Bay Area added 64,000 in jobs. In the same year, only 5,000 new homes were built.

F)With the average house in the city costing over $1.25 million and average flat prices over $1.11 million, the minimum qualifying income to purchase a house has increased to $254,000. Considering that the average household income in the city currently stands at around $80,000, it is not an exaggeration to say that the dream of home ownership is now beyond the grasp of the vast majority of today's people who rent.

G)For generations, the stability and prosperity of the American middle class has been anchored by home ownership. Studies have consistently shown that the value of land has overtaken overall income growth, thus providing a huge advantage to property owners as a vehicle of wealth building. When home prices soar above the reach of most households, the gap between the rich and the poor dramatically increases.

H)If contributing factors leading to housing becoming less than affordable are not resolved over multiple generations, a small elite will control a vast share of the country's total wealth. The result? A society where the threat of class warfare would loom large. A society's level of happiness is tied less to measures of quantitative wealth and more to measures of qualitative wealth. This means that how a person judges their security in comparison to their neighbors' has more of an impact on their happiness than their objective standard of living. At the same time, when a system no longer provides opportunities for the majority to participate in wealth building, it not only robs those who are excluded from opportunities, but also deprives them of their dignity.

I)San Francisco and the Bay Area have long been committed to values which embrace inclusion and rejection of mainstream culture. To see these values coming apart so publicly adds insult to injury for a region once defined by its progressive social fabric. In the face of resentment, it is human to want revenge. But deteriorating policies such as heavily taxing technology companies or real estate developers are not likely to shift the balance.

J)The housing crisis is caused by two primary factors: the growing desirability of the Bay Area as a place to live due to its excellent economy, and our limited housing stock. Although the city is experiencing an unprecedented boom in new housing, more units are sorely needed. Protection policies were originally designed to suppress bad development and boost historic preservation in our urban areas. Now, too many developers are experiencing excessive delays. Meanwhile, there are the land limitations of the Bay Area to consider. The region is surrounded by water and mountains. Local governments need to aid development as well. This means increasing housing density throughout the region and building upwards while streamlining the approval process.

K)Real estate alone will not solve the problem, of course. Transportation, too, needs to be updated and infrastructure extended to link distant regions to Silicon Valley and the city. We need to build an effective high-speed commuting system linking the high-priced and crowded Bay Area with the low-priced and low-density Central Valley. This would dramatically reduce travel times. And based on the operating speeds of hovering trains used in countries such as Japan or Spain, high-speed rail could shorten the time to travel between San Francisco and California's capital, Sacramento, or from Stockton to San Jose, to under 30 minutes. This system would bring once distant regions within reasonable commute to heavy job centers. The city also needs to update existing transportation routes combined with smart home-building policies that dramatically increase housing density in areas surrounding high-speed rail stations. By doing so, we will be able to build affordable housing within acceptable commuting distances for a significant bulk of the workforce.

L)Our threatening housing crisis forces the difficult question of what type of society we would like to be. Will it be one where the elite command the vast bulk of wealth and regional culture is defined by an aggressive business world? We were recently treated to a taste of the latter, when local tech employee Justin Keller wrote an open letter to the city complaining about having to see homeless people on his way to work.

M)It doesn't have to be this way. But solutions need to be implemented now, before angry crowds grow from a nuisance to serious concern. It may take less than you might think. And in fact, the solutions to our housing crisis are already fairly clear. We need to increase the density of housing units. We need to use existing technology to shorten travel times and break the land limits. There is a way to solve complex social and economic problems without abandoning social responsibility. This is the Bay Area's opportunity to prove that it can innovate more than just technology.

The suggestion that people should aim for dietary diversity by trying to eat a variety of foods has been a basic public health recommendation for decades in the United States and elsewhere. Now, however, experts are warning that aiming for a diverse diet may actually lead to just eating more calories, and, thus, to obesity. One issue is that people may not interpret "variety" the way nutritionists intend. This problem is highlighted by new research conducted by the American Heart Association. Researchers reviewed all the evidence published related to dietary diversity and saw a correlation between dietary diversity and a greater intake of both healthy and unhealthy foods. This had implications for obesity, as researchers found a greater prevalence of obesity amongst people with a greater dietary diversity. One author of the new study explained that their findings contradict standard dietary advice, as most dietary guidelines around the world include a statement of eating a variety of foods. But this advice does not seem to be supported by science, possibly because there is little agreement about the meaning of "dietary diversity, which is not clearly and consistently defined. Some experts measure dietary diversity by counting the number of food groups eaten, while others look at the distribution of calories across individual foods, and still others measure how different the foods eaten are from each other. Although the findings of this new study contradict standard dietary advice, they do not come as a surprise to all of the researchers involved. Dr. Rao, one of the study authors, noted that, after 20 years of experience in the field of obesity, he has observed that people who have a regimented lifestyle and diet tend to be thinner and healthier than people with a wide variety of consumption. This anecdotal evidence matches the conclusions of the study, which found no evidence that dietary diversity promotes healthy body weight or optimal eating patterns, and limited evidence shows that eating a variety of foods is actually associated with consuming more calories, poor eating patterns and weight gain. Further, there is some evidence that a greater variety of food options in a single meal may delay people's feeling of fullness and actually increase how much they eat. Based on their findings, the researchers endorse a diet consisting of a limited number of healthy foods such as vegetables, fruits, grains, and poultry. They also recommend that people simultaneously endeavor to restrict consumption of sweets, sugar and red meat. The researchers stress, however, that their dietary recommendations do not imply dietary diversity is never positive, and that, in the past, diversity in diets of whole, unprocessed food may have actually been very beneficial.

The ability to make inferences from the same and different, once thought to be unique to humans, is viewed as a cornerstone of abstract intelligent thought. A new study, however, has shown that what psychologists call same-different discrimination is present in creatures generally seen as unintelligent: newborn ducklings (小鸭). The study, published Thursday in Science, challenges our idea of what it means to have a birdbrain, said Edward Wasserman, an experimental psychologist at the University of Iowa who wrote an independent review of the study. "In fact, birds are extremely intelligent and our problem pretty much lies in figuring out how to get them to 'talk' to us, or tell us how smart they really are," he said. Antone Martinho and Alex Kacelnik, co-authors of the new paper, devised a clever experiment to better test bird intelligence. First, they took 1-day-old ducklings and exposed them to a pair of moving objects. The two objects were either the same or different in shape or color. Then they exposed each duckling to two entirely new pairs of moving objects. The researchers found that about 70% of the ducklings preferred to move toward the pair of objects that had the same shape or color relationship as the first objects they saw. A duckling that was first shown two green spheres, in other words, was more likely to move toward a pair of blue spheres than a mismatched pair of orange and purple spheres. Ducklings go through a rapid learning process called imprinting shortly after birth—it's what allows them to identify and follow their mothers. These findings suggest that ducklings use abstract relationships between sensory inputs like color, shape, sounds and odor to recognize their mothers, said Dr. Kacelnik. By studying imprinting, the authors of this study have shown for the first time that an animal can learn relationships between concepts without training, said Jeffrey Katz, an experimental psychologist at Auburn University who was not involved in the study. Previous studies have suggested that other animals, including pigeons, dolphins, honeybees and some primates (灵长类动物), can discern same from different, but only after extensive training. Adding ducklings to the list- particularly untrained newborn ducklings -- suggests that the ability to compare abstract concepts "is far more necessary to a wider variety of animals' survival than we previously thought," Dr. Martinho said. He believes the ability is so crucial because it helps animals consider context when identifying objects in their environment. It's clear from this study and others like it that "animals process and appreciate far more of the intricacies in their world than we've ever understood," Dr. Wasserman said. "We are in a revolutionary phase in terms of our ability to understand the minds of other animals."