Question 22 is based on the recording you have just heard.

Recording Three

听力原文

        Good morning, class, my topic today is how to feed a hungry world. The world’s population is expected to grow from 6.8 billion today to 9.1 billion by 2050. Meanwhile, the world’s population more than doubled from 3 billion between 1961 and 2007. Simultaneously, food production has been constrained by a lack of scientific research. Still, the task of feeding the world’s population in 2050 seems “easily possible”.

        What is needed is a second green revolution. This is an approach that is described as the “sustainable growth of global agriculture”. Such a revolution will require a wholesale shift of priorities in agricultural research. (22) [There is an urgent need for new crop varieties.] They must offer higher yields but use less water, nitrogen-rich fertilizers or other inputs. These new crops must also be more resistant to drought, heat and pests. Equally crucial is lower-tech research into basics such as crop rotation, and mixed farming of animals and plants on small farms.

        Developing nations could score substantial gains in productivity by making better use of modern technologies and practices. But that requires money. It is estimated that to meet the 2050 challenge, investment must double to US$83 billion a year. (23) [Most of that money needs to go towards improving agricultural infrastructure.] Everything from production to storage and processing must improve. However research agendas need to be focused on the needs of the poorest and most resource-limited countries. It is there that most of the world’s population lives, and it is there that population growth over the next decades will be the greatest.

        (24) [To their credit, the world’s agricultural scientists are embracing such a broad view. In March, for example, they came together at the first Global Conference on Agricultural Research, to begin working out how to change research agendas to help meet the needs of farmers in poorer nations.] But these plans will not bear fruit unless they get considerably more support from policy-makers.

         The growth in public agricultural-research spending peaked in the 1970s and has been shrinking ever since. (25) [The big exception is China, where spending has far surpassed other countries over the past decade.] China seems set to transition to become the key supplier of relevant science and technology to poorer countries. But developed countries have a humanitarian responsibility, too. Calls by scientists large increases in the appropriation of funds for public spending on agricultural research are more than justified.

22. What is an urgent need for feeding the world’s population in 2050 according to the speaker? （根据讲话者所说，到2050年养活世界人口的迫切需要是什么？）

解析：A。录音开头讲话者就说今天的主题是如何养活一个饥饿的世界，在后面又提到，新的作物品种成为一种迫切需求。A项符合题意，其中new varieties of crops是录音中new crop varieties的同义替换，故为正确答案。

错项排除：B项的cope with climate change在录音中无依据，故排除。录音中提到，新作物还必须更耐干旱、高温和虫害（pests），但并没有说要开发杀虫剂（pesticides），故C项排除。录音中提到，新的作物必须提供的产量更高，但对于水、富氮肥料（nitrogen-rich fertilizers）或其他投入的使用更少（less），D项说富氮肥料施用更多，与录音相悖，故排除。