1.Before I make my presentation,I'd like to show everyone a film:"An Inconvenient Truth" (不知道你是要放整个电影还是选段,如果是选段,那就说 a clips from "An Inconvenient Truth"或者a part of the film "An Inconvenient Truth.").OK,let's begin (或者说Alright,let's get it started之类的).I think many of you will be astounded by it.
2.extinction of species
3.global warming
4.ozone hole
5.In 1994,the area of ozone layer above the South Pole that was damaged reached 240 million (英语的计数方法是240,000,000) kilometer squared.
The ozone layer above the South Pole is formed in the past 2 billion (billion = 十亿）years,but 60% of it was damaged already in the last century.
The ozone layer above Europe and North America has decreased from 10% to 15%,Siberia even lost 35% of its ozone layer.
Strong ultraviolet light (UV light)'s radiation could cause a 3% increase in the chance of skin cancer.It also could cause cataract,defects in immune system,stagnation of growth,and other problems.