16. The word "peak" in line 19 is closest in meaning to

　　（A） pointed

　　（B） dismal

　　（C） mountain

　　（D） maximum

　　17. When was the birth rate in Canada at its lowest postwar level？

　　（A） 1966

　　（B） 1957

　　（C） 1956

　　（D） 1951

　　18. The author mentions all of the following as causes of declines in population growth after 1957 EXCEPT

　　（A） people being better educated

　　（B） people getting married earlier

　　（C） better standards of living

　　（D） couples buying houses

　　19. It can be inferred from the passage that before the industrial Revolution

　　（A） families were larger

　　（B） population statistic were unreliable

　　（C） the population grew steadily

　　（D） economic conditions were bad

　　20. The word "It" in line 34 refers to

　　（A） horizon

　　（B） population wave

　　（C） nine percent

　　（D） first half

　　21. The phrase "prior to" in line 36 is closest in meaning to

　　（A） behind

　　（B） Since

　　（C） During

　　（D） Preceding

　　Questions 22-30

　　Are organically grown foods the best food choices？ The advantages claimed for such foods over conventionally grown and marketed food products are now being debated. Advocates of organic foods - a term whose meaning varies greatly - frequently proclaim that such products are safer and more nutritious than others.

　　The growing interest of consumers in the safety and more nutritional quality of the typical North American diet is a welcome development. However， much of this interest has been sparked by sweeping claims that the food supply is unsafe or in adequate in meeting nutritional needs. Although most of these claims are not supported by scientific evidence， the preponderance of written material advancing such claims makes it difficult for the general public to separate fact from fiction. As a result， claims that eating a diet consisting entirely of organically grown foods prevents or cures disease or provides other benefits to health have become widely publicized and form the basis for folklore.

　　Almost daily the public is besieged by claims for "no-aging" diets， new vitamins， and other wonder foods. There are numerous unsubstantiated reports that natural vitamins are superior to synthetic ones， that fertilized eggs are nutritionally superior to unfertilized eggs， that untreated grains are better than fumigated grains and the like.

　　One thing that most organically grown food products seem to have in common is that they cost more than conventionally grown foods. But in many cases consumers are misled if they believe organic foods can maintain health and provide better nutritional quality than conventionally grown foods. So there is real cause for concern if consumers， particularly those with limited incomes， distrust the regular food and buy and buy only expensive organic foods instead.