英语专业四级考试听力复习材料：Our Concern

　　The history of life on earth has been a history of interaction between living things and their surroundings. To a large extent, the physical form and the habits of the earth’s vegetation and its animal life have been molded by the environment. Only in the present century has one species of man acquired significant power to alter the nature of his world.
　　The rapidity of change follows the pace of man rather than the pace of nature. Radiation is now the unnatural creation of man’s tampering with the atom. The chemicals are the creations of man’s inventive mind, having no counterparts in nature.
　　We have put poisonous and biologically potent chemicals into the hands of persons largely ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these enormous numbers of people to contact with these poisons, without their consent and often without their knowledge. We have allowed these chemicals to be used with little or no advance investigation of their effect. Future generations are unlikely to forgive our lack of concern.