单选题：Dangerous Sunshine to Children　　Two United Nations’agencies

　　Dangerous Sunshine to Children
　　Two United Nations’agencies warned on Tuesday that children are most at risk of developing skin cancers as a resuit of the long—term decline in the earth’s protective ozone layer．The agencies．the World Health Organization (WHO)and the UN Environmental Programme(UNEP)，issued the warning as they launched a global programm aimed at altering schools to the dangers of exposure to the sun．
　　“As ozone depletion becomes more marked．and as people around the world engage more in sun—seeking behavior，the risk of health complications from overexposure to ultra—violet radiation is becoming a substantial public health concern。”said WHO Director—general’Lee Jong—wook．By reducing the time children and adolescents are exposed to direct sunlight，he said“We can substantially reduce the risk of contracting skin cancers，cataracts and other conditions which might only appear much later in life．”
　　In its 2002 World Health Report，the WHO said around the world an average of 66，000 people died every year from melanoma or other types of skin cancer．Independent scientific research shows that every year there are between two to three million new cases’of non—malignant melanoma and around 130．000 malignant and normally fatalnew full-blown skin cancer cases．
　　Although most known skin cancers seemed to occur in the industrialized world，WHO radiation and environment health specialist Mike Repachoh told a news Conference，there were many cases believed to be unreported in poorer
　　countries．Ahhough people with darkerskins were less susceptible to akin cancers，they were just as likely to contract eye eataraetsas fairer—skinned populations．and people living close to the equator were even more likely to develop them．
　　As for the protection method，the WHO said that under the school plan，dubbed the Intersun Projeet，the two agencies will distribute packages showing teachers how to develop their own sun education programs，the WHO said．In a joint Statement from the two agencies which also marked the International Day for the preservation of the Ozone Layer，UNEP Executive Director’Klaus Toepfer said latest studies showed the protective shield was on the road to recovery．This was the result of international agreements over the decades to phase out use of various chemicals—like those used in some pesticides，refrigerators and aerosols．
　　“But we must remain vigilant and more needs to be done before we can say the problem is solved for good”．“said toepfer．This included stopping illegal trade in chemicals and enforcing the agreements in developing countries．”0nly then can we say the sky above our heads will be safe for our children and their children to come，the German environment minister said．
Why does the risk of developing skin cancers in children become greater and greater
A．Because they pay little attention to their skin health．
B．Because they are short of physical training