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  3. Some of the world’s most significant problems never hit headlines．One example...

Some of the world’s most significant problems never hit headlines．One example...

admin2020-12-24  17
问题 Some of the world’s most significant problems never hit headlines．One example comes from agriculture．Food riots and hunger make news．But the trend lying behind these matters is rarely talked about．This is the decline in the growth in yields of some of the world’s major crops．A new study by the University of Minnesota and McGill University in Montreal looks at where，and how far，this decline
is occurring．
The authors take a vast number of data points for the four most important crops：rice，wheat，corn and soybeans．They find that on between 24％and 39％of all harvested areas，the improvement in yields that took place before the 1980s slowed down in the l990s and 2000s．
There are two worrying features of the slowdown．One is that it has been particularly sharp in the world’s most populous countries，India and China．Their ability to feed themselves has been an important source of relative stability both within the countries and on world food markets．That self-sufficiency cannot be taken for granted if yields continue to slow down or reverse．
Second，yield growth has been lower in wheat and rice than in corn and soybeans．This is problematic because wheat and rice are more important as foods，accounting for around half of all calories consumed．Corn and soybeans are more important as feed grains．The authors note that“we have preferentially focused our crop improvement efforts on feeding animals rather than on crops that
feed people and are the basis of food security in much of the world．”
The report qualifies the more optimistic findings of another new paper which suggests that the world will not have to dig up a lot more land for farming in order to feed 9 billion people in 2050，as the Food and Agriculture Organization has argued．Instead，it says，thanks to slowing population growth，land currently ploughed up for crops might be able to revert to forest or wilderness．This could happen．The trouble is that the forecast assumes continued improvements in yields，which may not actually happen．
What does the new study by the two universities say about recent crop improvement efforts
选项 A.They fail to produce the same remarkable results as before the 1980s．

B.They contribute a lot to the improvement of human food production．

C.They play a major role in guaranteeing the food security of the world．

D.They focus more on the increase of animal food than human food grains．
答案D
解析细节理解题。由第四段最后一句话可知，人们更关注饲养动物的农作物的改良。
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