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1.Agricultural innovation has long sustained the world’s masses with an abundance of low-cost food,thanks to the success of the mid-20th century’s Green Revolution,which brought industrialization and high-yield grains to India,Mexico and many other developing countries.

2.The flow of electrons is from the negative zinc plate to the positive copper plate.

3.Some researchers speculate that overfishing may have caused a shift in predator dominance that is now making it nearly impossible for young seals to compete for food.

4.The addition of 2 percent sodium carbonate to boiling water increases the bactericide effect.

5.The possibility of a multiverse comes from inflation theory,the idea that our universe went through a rapid expansion shortly after the big bang.

6.Previous work has shown that people with schizophrenia also have lower dopamine receptor activity in the thalamus—and the scientists suggest in their paper that this striking similarity demonstrates a “crucial” link between creativity and psychopathology.

7.The behavior,known as discontinuous gas exchange,is seen only in certain insects,and only when they are in a resting state.

8.The 2010 meteorological year,which ended on 30 November,was the warmest in NASA’s 130-year record.

9.The record temperatures occurred despite a moderate occurrence of La Niña,a phenomenon over the Pacific Ocean that tends to lead to cooler temperatures at the surface,affecting the global mean.

10.Now research in honeybees offers evidence that learning ability is indeed linked with a general capacity to withstand one of the rigors of aging—namely,oxidative stress.

（II）篇章翻译练习

1.Our world is warming up.Climate models predict that this increase in mean annual temperature will continue for the rest of the 21st century.Whatever the reasons for the temperature increase,there is accumulating evidence that climate change may have a stronger impact on ecological processes than previously realized.They show that large-scale regional variations in climate have a twofold effect on the demographics of a migratory bird species,affecting both its survival in the tropics as well as its reproductive performance in the north.One frightening consequence of these findings is that they illustrate how difficult it will be to reliably predict the effects of large-scale regional climate change on ecological systems.

The El Niño Southern Oscillation (ENSO)—a quasi-periodic annual variation in global atmospheric and oceanic circulation patterns—influences rainfall worldwide.A quantitative measure of ENSO is provided by the Southern Oscillation Index (SOI),which is a standardized measure of the difference in atmospheric pressure between Tahiti in the South Pacific and Darwin in Australia.El Niños,assigned a low (negative) SOI value,generate milder and drier winters in the Southern Hemisphere.In contrast,high (positive) SOI values indicate La Niña conditions with more rainfall.

There has been an alarming decline in many migratory bird species that travel long distances to their tropical wintering grounds.It is well established that climate conditions at the wintering grounds may affect population fluctuations in long-distance migrant bird species.For instance,the size of the Dutch population of the purple heron,which winters in West Africa,is directly related to the annual variation in water discharges of the Senegal and Niger rivers.Small heron populations predominate after dry years when the rivers have little water.Another example is the British population of the sedge warbler.This increased after several winters of heavy rain in their West African wintering grounds,most likely because of higher survival rates among adult birds owing to an increase in the food supply.Such evidence suggests that unfavorable climate conditions at wintering grounds may explain the decline in many longdistance migratory bird species.The study of Sillett et al.provides the first evidence that the demographics of a migrant bird,the black-throated blue warbler,may be strongly influenced by large-scale climate changes affecting not only survival in southern wintering grounds but also reproductive performance in northern breeding areas.

The black-throated blue warbler is a migrant songbird that breeds in forests in eastern North America and winters primarily in the Greater Antilles (in the Caribbean).Sillett and coworkers took advantage of a long-term data set (1986 to 1998) from Hubbard Brook Experimental Forest in New Hampshire,USA (the warbler’s breeding ground),and from northwest Jamaica in the West Indies (the warbler’s winter quarters).With the Hubbard Brook data set they were able to show that the fecundity rate was lower under El Niño conditions than in La Niña years.They attributed this to an effect on the body mass of the fledglings,which is closely associated with the probability of first-year adult survival in many small songbird(passerine) species.Often the fecundity rate of small passerines is limited by food availability.Accordingly,Sillett et al.showed that,under El Niño conditions,there was a reduction in the biomass of lepidopteran larvae,the favorite food of the warbler.As a consequence,El Niño(with a low SOI value) resulted in a decrease in the number of new yearlings entering the New Hampshire population the following year.

2.In many developing countries,forest restoration at home has led to deforestation abroad,according to a new study in the Proceedings of the National Academy of Sciences (PNAS).The authors say their findings could have significant implications for ongoing efforts to protect the world’s remaining forests,which are disappearing at an annual rate of more than 32 million acres—an area roughly the size of England.

“Reducing deforestation is an international priority,given its impacts on carbon emissions and biodiversity,” said study co-author Eric Lambin of Stanford University in California and the University of Louvain in Belgium.“However,our study found that strengthened forestconservation policies and economic expansion often increased the demand for imported timber and agricultural products,which contributed to deforestation abroad.”

In the study,Lambin and co-authors Patrick Meyfroidt (University of Louvain) and Thomas Rudel (Rutgers University) analyzed the relationship between reforestation at the national scale and the international trade in forest and agricultural products between 1961 and 2007.The researchers focused on six developing countries—China,Chile,Costa Rica,El Salvador,India and Vietnam—that underwent a shift from net deforestation to net reforestation during that period.

Exporting deforestation

In five of the six countries (with the exception of India),the return of native forests was accompanied by a reduction in timber harvests and new farmland,thus creating a demand for imported wood and agricultural products.

“For every 100 acres of reforestation in these five countries,they imported the equivalent of 74 acres of forest products,” said Meyfroidt,a postdoctoral researcher at Louvain and lead author of the study.“Taking into account their exports of agricultural products,the net balance amounted to 22 acres of land used in other countries.”

During the past five years,the net land-use displacement increased to 52 acres of imported agricultural or forestry products for every 100 acres reforested,he added.That is,for every acre of reforested land,a half-acre was used elsewhere,including countries like Brazil and Indonesia,which together accounted for 61 percent of the all deforestation in the humid tropics between 2000 and 2005.