2011年1月8日雅思(阅读)真题试卷(题后含答案及解析).pdf

2011 年1 月8 日雅思（阅读）真题试卷(题后含答案及解析) 题型有：1. You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below.Going BananasThe world ’s favourite fruit could disappear forever in 10 years’ time.The banana is among the world ’s oldest crops. Agricultural scientists believe that the first edible banana was discovered around ten thousand years ago. It has been at an evolutionary standstill ever since it was first propagated in the jungles of South-East Asia at the end of the last ice age. Normally the wild banana, a giant jungle herb called Musa acuminata, contains a mass of hard seeds that make the fruit virtually inedible. But now and then, hunter-gatherers must have discovered rare mutant plants that produced seedless, edible fruits. Geneticists now know that the vast majority of these soft-fruited plants resulted from genetic accidents that gave their cells three copies of each chromosome instead of the usual two. This imbalance prevents seeds and pollen from developing normally, rendering the mutant plants sterile. And that is why some scientists believe the world ’s most popular fruit could be doomed. It lacks the genetic diversity to fight off pests and diseases that are invading the banana plantations of Central America and the smallholdings of Africa and Asia alike.In some ways, the banana today resembles the potato before blight brought famine to Ireland a century and a half ago. But “it holds a lesson for other crops, too”, says Emile Frison, top banana at the International Network for the Improvement of Banana and Plantain in Montpellier, France. “The state of the banana”, Frison warns, “can teach a broader lesson: the increasing standardisation of food crops round the world is threatening their ability to adapt and survive.”The first Stone Age plant breeders cultivated these sterile freaks by replanting cu