It starts in the Pacific Ocean and is thought to be caused by a failure in the trade winds(信風(fēng)), which affects the ocean currents driven by these winds. As the trade winds lessen in 48 , the ocean temperatures rise, causing the Peru current flowing in from the east to warm up by as much as 5 °C.
　　The warming of the ocean has far-reaching effects. The hot, humid (潮濕的) air over the ocean causes severe 49 thunderstorms. The rainfall is increased across South America, 50 floods to Peru. In the West Pacific, there are droughts affecting Australia and Indonesia. So while some parts of the world prepare for heavy rains and floods, other parts face drought, poor crops and 51.
　　El Nino usually lasts for about 18 months. The 1981-83 El Nino brought the most 52 weather in modern history. Its effect was worldwide and it left more than 2,000 people dead and caused over eight billion pounds 53 of damage. The 1990 El Nino lasted until June 1995. Scientists 54 this to be the longest El Nino for 2,000 years.
　　Nowadays, weather experts are able to forecast when an El Nino will 55 , but they are still not 56 sure what leads to it or what affects how strong it will be.
　　A) estimate
　　B) strength
　　C) deliberately
　　D) notify
　　E) tropical
　　F) phenomenon
　　G) stable
　　H) attraction
　　I) completely
　　J) destructive
　　K) starvation
　　L) bringing
　　M) exhaustion
　　N) worth
　　O) strike
　　參考答案：
　　47. P phenomenon
　　48. B strength
　　49. E tropical
　　50. L bringing
　　51. K starvation
　　52. J destructive
　　53. N worth
　　54. A estimate
　　55. O strike
　　56. I completely

2006年12月英語四六級(jí)考試最后沖刺專題