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间、混、套作增产的原因，主要有(1)()；(2)？()；(3)边行效应；(4)作物间互利关系；(5)增强抗灾能力。[每空1分]

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我国农业现代化与一些已经实现农业现代化的国家相比，有三个重要区别。第一，基础不同；第二()；第三，()。[每空1分]

Last Friday an advisory panel to the European Environment Agency issued an extraordinary scientific opinion: The European Union should suspend its goal of having 10 percent of transportation fuel made from biofuel by 2020.
The European Union&39;s biofuel targets were increased and extended from 5.75 percent by 2010 to 10 percent by 2020 just last year. Still, Europe&39;s well-meaning rush to biofuels, the scientists concluded, had produced a slew of harmful ripple effects - from deforestation in Southeast Asia to higher prices for grains.
In a recommendation released last weekend, the 20-member panel, made up of some of Europe&39;s most distinguished climate scientists, called the 10 percent target "overambitious" and an "experiment" whose "unintended effects are difficult to predict and difficult to control."
"The idea was that we felt we needed to slow down, to analyze the issue carefully and then come back at the problem," Laszlo Somlyody, the panel&39;s chairman and a professor at the Budapest University of Technology and Economics, said in a telephone interview.
He said that part of the problem was that when it set the targets, the European Union was trying desperately to solve the problem of rising transportation emissions "in isolation," without adequately studying the effects of other sectors like land use and food supply.
"The starting point was correct: I&39;m happy that the European Union took the lead in cutting greenhouse gasses and we need to control traffic emissions," Somlyody said. "But the basic problem is it thought of transport alone, without considering all these other effects. And we don&39;t understand those very well yet." The panel&39;s advice is not binding and it is not clear whether the European Commission will follow the recommendation.
It has become increasingly clear that the global pursuit of biofuels - encouraged by a rash of targets and subsides in both Europe and the United States - has not produced the desired effect.
Investigations have shown, for example, rain forests and peat swamp are being cleared to make way for biofuel plantations, a process that produces more emissions than the biofuels can save. Equally concerning, land needed to produce food forpeople to eat is planted with more profitable biofuel crops, and water is diverted from the drinking supply.
In Europe and the United States, food prices for items like pizza and bread have increased significantly as grain stores shrink and wheat prices rise.
The price of wheat and rice are double those of a year ago, and corn is a third higher, the UN Food and Agriculture Organization said this week.
"Food price inflation hits the poor hardest, as the share of food in their total expenditures is much higher than that of wealthier populations," said Henri Josserand of the Food and Agriculture Organization
For example, the European Environment Agency advisory panel suggests that the best use of plant biomass is not for transport fuel but to heat homes and generate electricity.
To be useful for vehicles, plant matter must be distilled to a fuel and often transported long distances. To heat a home, it can often be used raw or with minimal processing, and moved just a short distance away.

生态农业具有(1)绿色植被最大；(2)生物产量最高；(3)光合产物利用率最合理；(4)()；(5)()等特点。[每空1分]

尽管营业利润下降。琼斯集团公司仍保持了稳定的税后股权收益率，请解释它是如何操作的。