A、The improvement of agricultural infrastructure. B、The expansion of farmland in developing countries. C、The cooperation of the

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. 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 $83 billion US dollars a year. 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. 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. 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 for 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?
    23.Where should most of the money be invested to feed the ever-growing population?
    24.Why does the speaker give credit to the world’s agricultural scientists?
    25. What makes China exceptional in comparison with the rest of the world?