EI NIno is name given to the masterious and often unpredictable change in the climate of the world.This strange __1__ happens every five to eight years.It starts in the PAacific Ocean and is thought to be caused by a failure in the trade winds(信风)，which affects the ocean currents driven by these winds. As the trade winds lessen in __2__, the ocean comperatures rise causing the Peru current flowing in form the east to warm up by as much as 5°C.

The warming of the ocean has far-reaching effects.The hot,humid(潮湿的)air over the ocean causes severe __3__ thunderstorms.The rainfall is increased acrossAounth American __4__ floods to Peru.In the West pacific,there are droughts affecting Australia and Indonesia.So while some parts of the world perpare for heavy rains and floods,other parts face drought,poor crops and __5__.

EI Nino usually lasts for about 18 months The 1982-83 EI Nino brough the most __6__weather in mordern history. Its effect was worldwide and it left more than 2,000 people dead and caused over eight billion pounds __7__ of damage.The 1990 EI Nino will __9__, but they are still not __10__ 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

参考答案：

1.P phenomenon

2.B strength

3.E tropical

4.L bringing

5.K starvation

6.J destructive

7.N worth

8.A estimate

9.O strike

10.I completely