话题语篇导读

In the past hundred years a million people have died in earthquakes，another million have been killed by hurricanes and tornadoes and 9 million have lost their lives in floods.In addition to this，many millions more have died as a result of hunger and disease.We should also not forget in many of the world’s countries drought and serious water shortage are facts of life，especially in the African Sahel area bordering the Sahara Desert.