【正确答案】
B
【答案解析】[听力原文] A disease called 'Panama' is threatening supplies of the world's most popular fruit—banana. Two years ago, the United Nations warned that the 'Panama disease' could destroy 'much of the world's banana crop.' Since then, things have not gotten better. A new outbreak was discovered last year in Australia. The disease started in Asia in the 1990s, and later spread to Africa and the Middle East. World health officials worry the disease could travel to Latin America, one of the top banana producers in the world. All this is a big concern because bananas are an important source of income and nutrients for millions of people. They are grown in 135 tropical nations. The United Nations lists bananas as one of the most important foods, along with rice, wheat and corn. In 2011, farmers produced 107 metric tons, the UN said. What do you learn about 'Panama disease'?