【正文】 on and, above all, feeling needed and appreciated. 19. According to researchers, Richard Nixon39。t feel they39。s will to live。s health and resilience may also suffer after the loss of a spouse. In a 1987 study of widows, researchers from the University of California, Los Angeles, and UC, San Diego, found that they had a dramatic decline in levels of important immunesystem cells that fight off disease. Earlier studies showed reduced immunity in widowers. For both men and women, the stress of losing a spouse can have a profound effect. All sorts of potentially harmful medical problems can be worsened, says Gerald Davison, professor of psychology at the University of Southern California. People with high blood pressure, for example, may see it rise. In Nixon39。t know how to take care of ourselves. In one of several studies Helsing has conducted on bereavement, he found that widowed men had higher mortality rates than married men in every age group. But, he found that widowers who remarried enjoyed the same lower mortality rate as men who39。s wife of 53 years, died last June after a long illness. No one knows for sure whether her death contributed to his. After all, he was elderly and had a history of serious heart disease. Researchers have long observed that the death of a spouse particularly a wife is sometimes followed by the untimely death of the grieving survivor. Historian Will Durant died 13 days after his wife and collaborator, Ariel。s why this conference is so encouraging and so important it presents an excellent opportunity for the nations of the world to build cooperation and plan effective strategies and tactics. It won’t be easy. The alternative, however, is the continued internal decay of our societies. 12. Striking feature of the UN Conference on Drug Abuse is that ______. A. the delegates were unprecedentedly unanimous in their attempt to control drug abuse B. the conference touched upon many issues in the world. C. it was held by many countries. D. two documents were signed. 13. Many countries are shocked to find that _______. A. consuming countries are confronting a serious drug problem B. drug trafficking gangs are often allied with terrorists C. drug problem has bee more serious than ever D. drug abuse if undermining their government 14. According to the passage, which of the following is true? A. only those consuming countries are thought to have a serious drug problem B. the nations of the world do not have a consensus to find against drug problems. C. The United Nation Conference on Drug Abuse in Vienna was not very productive. D. The most important result of the United Nation Conference on Drug Abuse in Vienna was the drafting of two important documents. 15. Many countries have realized that the single way to control drugs is through ___________. A. cooperation in the developed countries B. cooperation in the developing countries C. domestic policies D. worldwide cooperation 16. According to the passage the drug problem for the developing countries is the most serious because ______. A. they lack necessary funding to curb drug abuse B. they are both producing and consuming countries of drugs C. they are not efficient in their attempt to bat drug abuse D. they have not enlisted support from developed countries 17. The delegates seemed to lack confidence in ______. A. curbing the demand for dangerous drugs B. destroying the process of distribution C. establishing system for collecting information about drug abuse. D. persuading people not to take drugs 18. According to the passage President Reagan ________. A. pointed out that the effort to bat drug abuse was inestimable B. expressed his doubt about the possibility of international agreement C. suggested that if drug abuse is not curbed, world civilization will degenerate D. said that the conference was encouraging and important because international cooperation is necessary. Passage 4 For much of the world, the death of Richard Nixon was the end of a plex public life. But researchers who study bereavement wondered if it didn39。s anchovy fishery by eating anchovy eggs. It may soon spread to western and northern European waters. The maritime nations that created the biological conveyor belt should support a coordinated international effort to find out what is going on and what should be done about it. 6. According to Dr. Carlton, ocean anisms are ____. A. being moved to new environments. B. destroying the pla. C. succumbing to the zebra mussel. D. developing alien characteristics. 7. Oceanographers are concerned because ____. A. their knowledge of this phenomenon is limited. B. they believe the oceans are dying. C. they fear an invasion from outerspace. D. they have identified thousands of alien webs. 8. It can be inferred from the article that banning ballast dumps in coastal waters proved successful in _______. A. North American Inland Waterway B. the globe C. Europe D. America 9. According to Marine ecologists, transplanted marine species ____. A. are all patible with one another. B. may upset the ecosystems of coastal waters. C. can only survive in their home waters. D. sometimes disrupt shipping lanes. 10. The identified cause of the problem is ____. A. the rapidity with which larvae mature. B. a mon practice of the shipping industry. C. a centuries old species. D. the world wide movement of ocean currents. 11. The article suggests that a solution to the problem ____. A. is unlikely to be identified. B. must precede further research. C. is hypothetically easy. D. will limit global shipping. Passage 3 The United Nation Conference on Drug Abuse that took place earlier this year in Vienna, was a very productiv