Directions: In this section, there is a short passage with 5 questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words. Please write your answers on Answer Sheet 2.
　　Questions 47 to 51 are based on the following passage.

　　Rocketing food prices, some of which have more than doubled in two years, have sparked riots in numerous countries recently. Millions are complaining and governments are scrambling to staunch (阻止) a fast-moving crisis before it spins out of control. From Mexico to Pakistan, protests have turned violent. Rioters tore through three cities in the West African nation of Burkina Faso last month, burning government buildings and looting (抢劫) stores. Days later in Cameroon, a taxi drivers’ strike over fuel prices changed into a massive protest about food prices, leaving around 20 people dead. Similar protests exploded in Senegal and Mauritania late last year. And Indian protesters burned hundreds of food-ration stores in West Bengal last October, accusing the owners of selling government-subsidized food on the lucrative black market.
　　“This is a serious security issue,” says Joachim von Braun, director-general of the International Food Policy Research Institute, in Washington. In recent weeks, he has been bombarded by calls from officials around the world, all asking one question: How long will the crisis last?
　　The forecast is grim. Governments might quell (平息) the protests, but bringing down food prices could take at least a decade, food analysts say. One reason: billions of people are buying ever-greater quantities of food, especially in booming China and India, where many have stopped growing their own food and now have the cash to buy a lot more of it. Increasing meat consumption, for example, has helped drive up demand for grain, and with it the price.
　　There are other problems too. The spike in oil prices, which hit $103 per barrel in recent days, has pushed up fertilizer prices, as well as the cost of trucking food from
　　farms to local markets and shipping it abroad. Then there is climate change. Harvests have been seriously disrupted by freak weather, including prolonged droughts in Australia and southern Africa, floods in West Africa, and this past winter’s deep frost in China and record-breaking warmth in northern Europe.
　　注意：此部分试题请在答题卡2上作答。
　　47. What triggered a violent protest about food prices in Cameroon?           .
　　48. According to Joachim von Braun, what worries officials all over the world?          .
　　49. By food analysts, what made it so difficult to bring down food prices in a short time?           .
　　50.           would go up with the increasing meat consumption everywhere on the globe.
　　51. The increase in oil prices has helped to boost the prices of fertilizer and that of          .
　　答案
　　47. A taxi drivers’ strike over fuel prices
　　48. The security problem caused by food shortage
　　49. Many people’s stopping growing food
　　50. The prices of grain
　　51. transportation of foods