《英语模板》PPT课件.ppt

,Plague(灾害)of locusts,Locust can live in the various places,such as the mountains,forests,low-lying areas,semi-arid（半干燥的)and grassland.Locust is an important pest of crops.They live through the three stages of life:fertilized egg,larva(幼虫),adult.,1.causes2.history 3.countermeasures,The reason,This picture refers to a locust disaster.Locust is extremely warm and dry,and often severe droug-hts and locust,the so-called“drought and locust”,“prolo-nged drought has locust(久旱必有蝗),The history,Locust is a worldwide catastrophe(灾变),with a long history,which is even mentioned in the Book of Songs（诗经）去其螟螣，及其蟊贼，无害我田稚。田祖有神，秉畀炎火,Su Shi in Qiantang Tokimi describes lo-cust as“nebula on the Sun and moon,hide under vegetation,when it falls,have ones eyes filled with desolately.Migratory locust to half when its dark.”。上翳日月，下掩草木，遇其所落，弥望萧然。飞蝗来时半天黑。,Disaster area,in 2001,Russia Sitaluoboer region in the South,2003 United States of Nevada,Western Utah and Idaho are suffering from falling prey to the locusts,Idahos disaster was the worst since the second world war.,2001 Liaoning province of China,the cause was the most serious drougth in the past one hundr-ed years.,Disaster prevention measures,Killing grasshoppers(another word of locust)was the main method long ago.At present,the most effective approach is to spray pesticides by plane.In effect,the cost is very high.,The end,Thank you!,