【正文】 4Some tropical termites are more ingenious engineers, constructing huge aboveground nests with builtin “air conditioning” that keeps the nest moist, at a constant temperature, and well supplied with oxygen. Among the most architecturally advanced of these termites is an African species, Macroternes natalensis. Renowned Swiss entomologist Martin Luscher described the mounds of this fungusgrowing species as being as much as 16 feet tall, 16 feet in diameter at their base, and with a cementlike wall of soil mixed with termite saliva that is from 16 to 23 inches thick. The thick and dense wall of the mound insulates the interior microclimate from the variations in humidity and temperature of the outside atmosphere. Several narrow and relatively thinwalled ridges on the outside of the mound extend from near its base almost to its top.According to luscher, a mediumsized nest of Macrotermes has a population of about 2 million individuals. The metabolism of so many termites and of the fungus that they grow in their gardens as food helps keep the interior of the nest warm and supplies some moisture to the air in the nest. The termites saturate the atmosphere of the nest, bringing it to about 100 percent relative humidity, by carrying water up from the soil.9. According to paragraphs 3 and 4, all of the following are true of the nests of Macroternes natalensis EXCEPT:A. The walls are built out of soil mixed with termite saliva.B. The nests can be as tall as they are wide at the base.C. The interior of the nest is kept as humid as possible.D. The termites use hollow, thinwalled ridges to travel from one part of the nest to another.Passage 4According to luscher, a mediumsized nest of Macrotermes has a population of about 2 million individuals. The metabolism of so many termites and of the fungus that they grow in their gardens as food helps keep the interior of the nest warm and supplies some moisture to the air in the nest. The termites saturate the atmosphere of the nest, bringing it to about 100 percent relative humidity, by carrying water up from the soil.10. According to paragraph 4, how does the fungus grown by Macrotermes natalensis affect the environment of the nest?A. It carries water up from the soil into the interior.B. It dries the air by using up moisture as it grows.C. It heats and adds humidity to the inside of the nest.D. It lessens the effects of the metabolism of so many termites.Passage 5But how is this wellinsulated nest ventilated? Its many occupants require over 250 quarts of oxygen (more than 1,200 quarts of aire) per day. How can so much oxygen diffuse through the thick walls of the mound? Even the pores in the wall are filled with water, which almost stops the diffusion of gases. The answer lies in the construction of the nest. The interior consists of a large central core in which the fungus is grown, below it is “cellar” of empty space, above it is an “attic” of empty space, and within the ridges on the outer wall of the nest, there are many small tunnels that connect the cellar and the attic. The warm air in the fungus gardens rises through the nest up to the attic. From the attic, the air passes into the tunnels in the ridges and flows back down to the cellar. Gases, mainly oxygen ing in and carbon dioxide going out, easily diffuse into or out of the ridges, since their walls are thin and their surface area is large because they protrude far our from the wall of the mound. Thus air that flows down into the cellar through the ridges is relatively rich in oxygen, and has lost much of its carbon dioxide. It supplies the nest’s inhabitants with fresh oxygen as it rises through the fungusgrowing area back up to the attic.11. According to paragraph 5, what does the thinness of the ridge walls make possible?A. The concentration of cool air in the cellarB. The construction of exceptionally long tunnelsC. The even distribution of oxygen from attic to cellarD. The diffusion of gases into and out of the ridges12. According to paragraph 5, what happens to the air in the ridge tunnels of Macrotermes natalensis nests?A. It bees more humid as water vapor diffuses into the tunnels.B. It loses carbon dioxide and gains oxygen.C. It reaches the interior of the nest through pores in the walls.D. It moves in the same direction as the air in the center of the nest.13. Paragraph 5 supports which of the following about the air that flows through the interior of a Macrotermes natalensis mound?A. It has a higher concentration of oxygen in the cellar than in the attic.B. It is the same temperature as the air on the outside of the mound.C. It contains over 250 quarts of oxygen which circulate continuously.D. It is most humid in the cellar and gradually loses moisture as it rises to the attic.14. Look at the four squares [■] that indicate where the following sentence could be added to the passage.If not through the walls or its pores, how does oxygen enter the nest at all, since the nest has a closed surface?Where would the sentence best fit? Click on a square [■] to add the sentence to the passage.But how is this wellinsulated nest ventilated? Its many occupants require over 250 quarts of oxygen (more than 1,200 quarts of aire) per day. How can so much oxygen diffuse through the thick walls of the mound? [■] Even the pores in the wall are filled with water, which almost stops the diffusion of gases. [■] The answer lies in the construction of the nest. [■] The interior consistsof a large central core in which the fungus is grown, below it is “cellar” of empty space, above it is an “attic” 。F for temperate zone species and about 86176。F for tropical species. Subterranean termites, the destructive species that occurs monly throughout the eastern United States, attain these conditions by nesting in moist soil that is in contact with wood, their only food. The surrounding soil keeps the nest moist and tends to keep the tem