此次考试阅读三篇分别考了海水净化系统，植物的防御和纺织业女性。
Passage1：
文章大意：介绍了海水利用的可能性以及如何利用的方法-海水净化。
题型：Blank Filling
TURE/FALSE/NOT GIVEN
Multiple Choice
Passage2:
文章大意：从chemical和physical的角度上面介绍了树的一些特征和影响，重点说明了树的自我防御。
题型：List of Headings
YES/NO/NOT GIVEN
多选题
Passage3
文章大意：提到了第一本女性杂志，并提到了纺织业以及女性在这个行业里所处的地位和作用。
题型：Multiple Choice
Summary
TRUE/FALSE/NOT GIVEN
二、类似阅读推荐
Solar-powered desalination will transform Navajo life
A scheme in Arizona using solar energy to power a water desalination plant aims to bring running water to thousands of people
THE sun beats down on sand dunes and cracked red soil as we rumble through the desert in a heavy-duty pickup truck. It is monsoon season in the Navajo Nation but the scenery looks as if it never got the memo. Two decades of severe drought have left the land parched.
"It's hard to imagine that 30 years ago this was all covered in knee-high grass," says Kevin Black, a Native American affairs specialist for the US Bureau of Reclamation. "Clean water has become the Navajo's most precious commodity."
Arizona's largest aquifer lies 120 metres beneath us, but the water is not drinkable. It's half as salty as seawater, and a 2008 study found that it contains dangerous levels of uranium and arsenic.
Black says piping water from a tribe-owned purification facility to homes scattered across an area the size of West Virginia is an economic impossibility. For 80,000 Navajo, this means no running water at home.
Instead, Navajo families drive hundreds of kilometres every month to collect water. "It is called water hauling," Black says. "It is an expensive and time-consuming journey that has become part of the Navajo way of life."
The Bureau of Reclamation and engineers at the University of Arizona think they have come up with a way to help, by building a self-sufficient, solar-powered desalination plant.
Black points out the budding facility perched on a hill in the south-western corner of the reservation (see map). Construction began in mid-August. On completion in 2013, it will produce close to 4000 litres of clean water a day, he says. With sufficient funding, the facility could be the first of a series across the reservation. That could halve the cost of hauling water.
Wendell Ela, the project's lead engineer, has been testing prototypes for the past year in Tucson. He says the process uses electricity from solar panels to pump contaminated water up from the aquifer and boil it.
The steam then passes through a series of membranes that filter out salt and other contaminants. As it cools, the difference in vapour pressure it creates draws more hot water vapour through the system. Purified water is then collected in an external condenser.
Although commercial desalination plants have been used in the Middle East and Australia since the early 1990s, they rely on reverse osmosis or multistage distillation - processes that are technically challenging and expensive to maintain.
By contrast, the team's membrane desalination system is ideal for an isolated population that does not have access to an electrical grid, Ela says. It is built using simple, low-tech, off-the-shelf components. The team is aiming to build a system lasting 30 to 40 years that would require only periodic maintenance. "We had to design the system to be within the capacity and budget of the water-users," he says.
Such reliability isn't guaranteed, says John Lienhard, an engineer at the Massachusetts Institute of Technology, who says the technology hasn't been around long enough to have much of a track record. And the systems cost up to $100,000 to build. But he says that should fall steeply as they gain wider adoption.
The impact on Navajo life would be profound. If the other planned desalination plants are built in the reservation, they could provide running water to tens of thousands of Navajo who have never had it.
"People always ask, 'If it is so bad why don't they leave?'" Black says. "My response is, 'Who are we to question them?' Their livelihood and culture has been intertwined with this place for thousands of years. We are trying to help them hold on to their identity in a world that is changing very fast."
Forestry: Planting the forest of the future
While conservation biologists debate whether to move organisms threatened by the warming climate, one forester in British Columbia is already doing it. Emma Marris reports.
At a research station in the Okanagan valley in British Columbia, a few kilometres outside the town of Vernon, orderly rows of trees run alongside the road. Many of the conifers stand tall and full, producing seeds destined for plantations around the province. But one dusty brown field is filled with lines of seedlings just ankle high. Greg O'Neill, 45, who planted the trees in April, walks among them with a slightly paternal air. They are part of a very slow experiment that will yield the first results that are useful to policy-makers just about in time for him to retire.
In a world in which many scientists fret about the toll that global warming is exacting on nature, O'Neill is actually doing something about it. A research scientist for the British Columbia Ministry of Forests, he is moving seedlings to areas that are outside their current comfort zone to test how they might handle the warmer conditions of the future. And he is behind a government push to move tree populations into new areas to prepare them for the warming climate.
Some hail the policy as pragmatic and forward-thinking, but others label it as dangerous and premature. Plants moved by humans may become invasive in their new haunts or just fail to thrive. Yet O'Neill thinks the potential gains in terms of timber production and forest health are worth the risk.
The Canadian province is a pioneer in the field of adaptation, according to Gerald Rehfeldt, a retired United States Forest Service geneticist based in Moscow, Idaho, who has long championed moving trees. "British Columbia is ahead of everybody in the western hemisphere," he says.
O'Neill's experiment is called the Assisted Migration Adaptation Trial (AMAT) and it is what foresters call a provenance trial. The AMAT is taking seedlings from 40 spots in British Columbia, Washington state, Oregon and Idaho and planting them in 48 sites all over those same areas. All told, 16 species are involved in the project (see Testing assisted migration).
One element of the project tests whether moving trees north will enable them to fare better as the climate changes around them. Another part of the experiment turns the clock forwards on the forests by taking commercially important trees and moving them south, forcing them to endure a warmer climate, quickly simulating years of climate change.
O'Neill expects 50% of his seedlings to die, mainly because trees are highly diverse genetically and are often adapted to specific local climates. Take a Douglas fir from the coast and bring it inland, and it may well die within a few years. If it doesn't, the chances are that it will be small, pest ridden or crooked. "Douglas fir grows from Mexico City to central British Columbia, but move it 700-metres elevation downhill at any location, and you will be growing toothpicks," says O'Neill.
Warmer woods
A prototype spruce-only provenance trial on an adjacent patch gives a preview of how some of these seedlings might look in five years. A few are about chest height, others are half or a quarter as tall. Some are dead or half dead, their tops dry and bent into a 'shepherd's crook', invaded by white pine weevil. In general, ones from farther away fare worse.
“Douglas fir grows from Mexico to British Columbia, but move it 700-metres elevation downhill and you will be growing toothpicks.”
O'Neill sees a similar pattern at older provenance plantings, some now 50 years old. These trials were planted before climate change was an acknowledged problem. The idea was to see if new combinations of populations and areas could lead to better yields — this works because trees are not always particularly well adapted to their locations.
Throughout the province, O'Neill thinks that many trees are already feeling the effects of climate change. "We see some really ugly trees out there," says O'Neill. "Maybe the pest and pathogen outbreaks we are seeing are compounded by that maladaptation."
The mountain pine beetle has spread through the province in recent years, turning healthy lodgepole pines a desiccated red colour as it kills them. So far, 14.5 million hectares are affected1 — an area larger than Greece. The warming of the climate is widely thought to be a factor in the outbreak — usually low temperatures in the winter would kill off much of the beetle population.
For the Northern Hemisphere, climate models agree that regions in the north will warm more and faster than areas nearer the equator. British Columbia had already warmed 0.7 °C in the decade to 2006 (ref. 2) — almost as much as the globe has warmed over the past century — and a middle-of-the-road climate simulation for British Columbia projects another half a degree increase every decade. The province is not alone in facing changes to its forests. One analysis suggests that 88% of the western United States will see a turnover in the kinds of tree communities it hosts by the end of the century3. On the other hand, the Intergovernmental Panel on Climate Change predicts that rising carbon dioxide levels will lead to more growth, creating bigger trees and boosting the forestry industry in some regions4.