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

　　(A) structures

　　(B) importance

　　(C) skeletons

　　(D) imprints　191. The woolly mammoth, a long-haired rhinoceros, and other mammals have been periodically exposed in the tundra of Siberia, the hair and red flesh still frozen in cold storage.

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

　　(A) photographed

　　(B) uncovered

　　(C) located

　　(D) preserved

　　192. A useful definition of an air pollutant is a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely.

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

　　(A) negatively

　　(B) quickly

　　(C) admittedly

　　(D) considerably

　　193. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycles.

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

　　(A) eliminated

　　(B) caused

　　(C) slowed

　　(D) changed

　　194. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities.

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

　　(A) harmful

　　(B) noticeable

　　(C) extensive

　　(D) weak

　　195. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0. 08 parts per million (ppm) , which is about 400 times its natural level.

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

　　(A) beneficial

　　(B) special

　　(C) measurable

　　(D) separable

　　196. The acute, growing public awareness of the social changes that had been taking place for some time was tied to tremendous growth in popular journalism in the late nineteenth century, including growth in quantity and circulation of both magazines and newspapers.

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

　　(A) useful

　　(B) intense

　　(C) genuine

　　(D) controversial

　　197. Furthermore, the introduction in 1890 of the first successful linotype machine promised even further growth. In 1872 only two daily newspapers could claim a circulation of over 100,000, but by 1892 seven more newspapers exceeded that figure. A world beyond the immediate community was rapidly becoming visible.

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

　　(A) controlled

　　(B) surpassed

　　(C) affected

　　(D) equaled

　　198. Magazines as they are known today began publication around 1882, and, in fact, the circulation of weekly magazines exceeded that of newspapers in the period which followed. By 1892, for example, the circulation of the Ladies' Home Journal had reached an astounding 700,000.