(C) mountain

　　(D) maximum

　　018. Although the growth in Canada's population had slowed down by 1966 (the increase the first half of the 1960's was only nine percent) , another large population wave was coming over the horizon. It would be composed of the children who were born during the period of the high birth rate prior to 1957.

　　The phrase "prior to" is closest in meaning to which of following?

　　(A) behind

　　(B) since

　　(C) during

　　(D) preceding

　　019. Advocates of organic foods --- a term whose meaning varies greatly --- frequently proclaim that such products are safer and more nutritious than others.

　　The word "Advocates" is closest in meaning to which of following?

　　(A) Proponents

　　(B) Merchants

　　(C) Inspectors

　　(D) Consumers

　　020. 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.

　　The word "unsubstantiated" is closest in meaning to which of following?

　　(A) unbelievable

　　(B) uncontested

　　(C) unpopular

　　(D) unverified