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TEXT A Basic to any understanding of Canada in the 20 years after the Second World War is the country’s impressive population growth. For every three Canadians in 1945, there were over five in 1966. In September 1966 Canada’s population passed the 20 million mark. Most of this surging growth came from natural increase. The depression of the 1930’s and the war had held back marriages, and the catching-up process began after 1945. The baby boom continued through the decade of the 1950’s, producing a population increase of nearly fifteen percent in the five years from 1951 to 1956. This rate of increase had been exceeded only once before in Canada’s history, in the decade before 1911, when the prairies were being settled. Undoubtedly, the good economic conditions of the 1950’s supported a growth in the population, but the expansion also derived from a trend toward earlier marriages and an increase in the average size of families. In 1957 the Canadian birth rate stood at 28 per thousand, one of the highest in the world. After the peak year of 1957, the birth rate in Canada began to decline. It continued falling until in 1966 it stood at the lowest level in 25 years. Partly this decline reflected the low level of births during the depression and the war, but it was also caused by changes in Canadian society. Young people were staying at school longer; more women were working; young married couples were buying automobiles or houses before starting families; rising living standards were cutting down the size of families. It appeared that Canada was once more failing into step with the trend toward smaller families that had occurred all through the Western world since the time to the Industrial Revolution. Although the growth in Canada’s population had slowed down by 1966 (the increase in the first half of the 1960’s was only nine percent), another large population wave was coming over the horizon. It would be compared to the children of the children who were born during the period of the high birth rate prior to 1957. The word "It" in line 3 of the last paragraph refers to ______.
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TEXT B Tomorrow evening about 20 million Americans will be shown, on their television screens, how easy it is to steal plutonium and produce "the most terrifying blackmail weapon ever devised"-a home-made atomic bomb. They will be told that no commercial nuclear plant in the United States - and probably in the World-is adequately protected against a well planned armed attack by terrorists, and that there is enough information on public record to guide a nuclear thief not only to the vaults of nuclear plants where plutonium is stored, but also to tell him how the doors of those vaults are designed. The hour-long television programme, "The Plutonium Connection", makes its point by showing how a 20-year-old student of the Massachusetts Institute of Technology in five weeks designed an atomic bomb composed of plutonium and parts from a hardware store. The young man, whose identity is being kept secret for fear he may be kidnapped by terrorists; is quoted as saying: "’I was pretty surprised about how easy it is to design a bomb. When I was working on my design, I kept thinking there’s got to be more to it than this, but actually there isn’t. It’ s simple." The student worked alone, using information he obtained from science libraries open to the public. The television programmes, produced for non-commercial stations across the country by a Boston educational station, shows how quantities of other "secret" information are available to anyone. The Atomic Energy Commission’s public reading room in Washington is described by the narrator as "the first place a bomb-designer would visit when he was planning his plutonium theft. On file there and freely available are the plans of every civilian nuclear installation in the country." The programme seems certain to create enormous controversy - not only. over the lack of nuclear safeguards, but also over the morality of commissioning the student to design a bomb and the wisdom of drawing attention to the ways that a nuclear thief can work. Even an Official of Public Broadcasting System, which is distributing the TV programmes, confessed to qualms: "It’s a terribly important subject, and people should know about the dangers, but I can’t help wondering if the programme won’t give someone ideas." "The Plutonium Connection" explains, for example, that the security system of nuclear plants were all designed to prevent sabotage by perhaps one or two agents of some foreign Power. But now this appears less of a hazard than the possibilities of an attack by an armed band of terrorists with dedicated disregard for their own lives. The programme discusses two major plutonium reprocessing plants in the US one already operating in Oklahoma, one being completed in South Carolina - neither of which has more than a handful of armed guards to supplement the alarms, fences and gun-detectors that Government security requires. Both are in such remote areas that it would take at least 45 minutes for a sizable police force to be assembles, if there were an attack. An official of the South Carolina plant - a joint operation of Allied Chemical, Gulf Oil and Royal Dutch Shell - admits to television viewers that the "system we’ve designed would probably not prevent" a band of about 12 armed terrorists from entering. Pilfering plutonium is even easier, the programme suggests. Despite constant inventories, there are inevitably particles of plutonium unaccounted for about 1 1b. a month at the Oklahoma plant, owned by the Kerr-McGee oil company, which in a year adds up to enough to make an atomic bomb. It is suggested that pilfering would be even easier if instrument technicians were unscrupulous enough to alter their measuring devices. The television film also shows radioactive fuel being transported to nuclear processing plants in commercial armoured cars. As a safety measure, US drivers of such cars are ordered to contact headquarters by radio telephone every two hours. But the equipment is "cumbersome and unreliable", and in difficult terrain there are radio blackout areas. The programme ends with a warning from Dr. Theodore Taylor, a former Atomic Energy Commission officer who has long contended that any person of modest technical ability could make an atomic bomb: "If we don’t get this problem under international control within the next five or six years, there is a good chance that it will be permanently out of control." What information will NOT be included in tomorrow’s TV programme
TEXT C Why would anyone want to set aside a day to honor a lowly little groundhog The answer to that question is not certain, but a group of people get together every February 2 in Punxsutawney, Pennsylvania, to watch Punxsutawney "Pete" leave his burrow. What "Pete" does next, many believe, will indicate whether spring is just around the comer or a long way off, You see, in Pennsylvania on this date there is usually a great deal of snow on the ground, and the little animal has been hibernating during the long, cold winter. He gorged himself during the autumn months and then went into his burrow for a long sleep, his body fat helping keep him alive. But as he emerges on February 2, he looks very thin. If the sun is shining brightly and he sees his shadow, according to legend, it scares him back into his home where he will stay another six weeks. Should it be cloudy and gray, the little animal will supposedly wander While many believe in the groundhog’s predictions, it is unwise to accept them as factual. What prediction does the groundhog supposedly make
You have been badly injured in a car accident. It is necessary to give you a blood transfusion because you lost a great deal of blood in the accident. However, special care must be taken in selecting new blood for you. If the blood is too different from your own, the transfusion could kill you. There are four basic types of blood: A, B, AB, and O. A simple test can indicate a person’s blood type. Everybody is born with one of these four types of blood. Blood type, like hair color and height, is inherited from parents. Because of substances contained in each type, the four groups must be transfused carefully. Basically, A and B cannot be mixed. A and B cannot receive AB, but AB may receive A or B. O can give to any other group; hence, it is often called the universal donor. For the opposite reason, AB is sometimes called the universal recipient. However, because so many reactions can occur in transfusions, patients usually receive only salt or plasma (liquid) until their blood can be matched as exactly as possible in the blood bank of a reactions to the transfusion. There is a relationship between your blood type and your nationality. Among Europeans and people of European ancestry, about 42 percent have type A while 45 percent have type O. The rarest is type AB. Other races have different percentages. For example, some American Indian groups have nearly 100 percent type O. If you need a transfusion, the best and safest blood for you is ______.
TEXT D Lichens can be spectacular for anyone who cares to look, but few people take the trouble. Often modestly colored, and seemingly two-dimensional as they cling to whatever surface they find, they grow in background - as though designed to be ignored. Yet they hold a special fascination for botanists, partly because they present mysteries still to be solved and partly because they do so many things so well. No casual observer ’of a lichen would ever suspect that it was a composite of interacting life forms. This seemingly uncomplicated lichen is actually composed of a fungus and a colony of algae (or blue-green algae, which some scientists now consider to be bacteria). A few species even include all three of these diverse forms of life. A complete lichen is strikingly different from its separated partners in both appearance and biochemistry-many produce unique compounds which cannot be made by the component organisms alone. Lichens grow in almost every natural habitat imaginable, from deserts to tropical rain forests-even on the backs of certain beetles in New Guinea, and i0side rocks (along with algae ) in the otherwise barren dry valleys of Antarctica. Many species can tolerate extreme heat, cold. or dryness. Very few, however, can survive heavy air pollution, and many live only where the air is very clean. The disappearance of lichens from an area gives warning of a threatened environment. The third paragraph passage mainly discusses ______.
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