141. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity-horned larks dig holes in the ground and ptarmigan burrow into snow banks-but the effect of sheltering is magnified by several birds huddling together in the roosts, as wrens, swifts, brown creepers, bluebirds, and anis do.

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

　　(A) caused

　　(B) modified

　　(C) intensified

　　(D) combined

　　142. The second possible benefit of communal roots is that they act as "information centers." During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat.

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

　　(A) fly

　　(B) assemble

　　(C) feed

　　(D) rest

　　143. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground.

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

　　(A) suggested

　　(B) negated

　　(C) measured

　　(D) shielded

　　144. Drying, smoking, and salting could preserve meat for a short time, but the availability of fresh meat, like that of fresh milk, was very limited; there was no way to prevent spoilage.

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

　　(A) estimate

　　(B) avoid

　　(C) correct

　　(D) confine

　　145. The icebox became a fixture in most homes and remained so until the mechanized refrigerator replaced it in the 1920's and 1930's. Almost everyone now had a more diversified diet.

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

　　(A) luxury item

　　(B) substance

　　(C) commonplace object

　　(D) mechanical device

　　146. Some people continued to eat mainly foods that were heavy in starches or carbohydrates, and not everyone could afford meat. Nevertheless, many families could take advantage of previously unavailable fruits, vegetables, and dairy products to achieve more varied fare.

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

　　(A) therefore

　　(B) because

　　(C) occasionally

　　(D) however

　　readily change its orientation, or phase. Cats know this instinctively, but scientists could not be sure how it happened until they increased the speed of their perceptions a thousand fold.

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

　　(A) only

　　(B) easily

　　(C) slowly

　　(D) certainly

　　147. The changing profile of a city in the United States is apparent in the shifting definitions used by the United States Bureau of the Census. In 1870 the census officially distinguished the nation's "urban" from its "rural" population for the first time.