【正文】 antle(B) crust(C) seabed(D) Earth39。 at greater depths, high temperatures(15)make the rock behave more like a liquid than a solid. Deeper still, the pressure is evenmore intense, preventing the rock from melting in spite of a higher temperature.Beyond a depth of around 2,900 kilometers, a great change takes place and themantle gives way to the core. Some seismic waves cannot pass through the core andothers are bent by it. From this and other evidence, geologists conclude that the outer(20)core is probably liquid, with a solid center. It is almost certainly made of iron, mixedwith smaller amounts of other elements such as nickel.The conditions in the Earth39。s interior. Some geologiststhought that it contained a highly pressed ball of incandescent gas, while others Line suspected that it consisted of separate shells, each made of a different material. Today,(5) well over a century later, there is still little direct evidence of what lies beneath ourfeet. Most of our knowledge of the Earth39。s honor, Hazen named it Streptomyces noursei, and within a year the two scientists knew (20) that the properties of their substance distinguished it from previously described antibiotics. After further research they eventually reduced their substance to a fine, yellow powder, which they first named fungiciden, then renamed nystatin (to honor the New York State laboratory) when they learned the previous name was already in use. Of their major discovery, Brown said lightly that it simply illustrated how unpredictable consequences can e from rather modest beginnings.45. What is the main topic of the passage?(A) The lives of Hazen and Brown. (B) The development of a safe fungicide. (C) The New York State Department of Health.(D) The development of penicillin. 46. What can be inferred from the passage about penicillin? (A) It effectively treats fungus infections. (B) It was developed before nystatin.(C) It was developed the Second World War. (D) One of the byproducts is nystatin. 47. Why does the author mention Columbia University in lines 10 and 11? (A) Hazen and Brown developed nystatin there.(B) Brown was educated there. (C) Hazen did research there. (D) It awarded a prize to Hazen and Brown. 48. The word both in line 11 refers to (A) Hazen and Brown (B) Penicillin and streptomycin (C) the Department of Health laboratories at Albany and New York (D) double effect 49. What substance did Brown and Hazen analyze? (A) Dirt (B) Streptomycin(C) Penicillin (D) Bacteria 50. Who was W. B. Bourse? (A) A microbiologist (B) A teacher of Hazen39。s work was stimulated by the wartime need to find a cure for the fungus infections that afflicted many military personnel. Scientists had been feverishly searching for an antibiotic (5) toxic enough to kill the fungi but safe enough for human use, since, unfortunately, the new wonder drugs such as penicillin and streptomycin killed the very bacteria in the body that controlled the fungi. It was to discover a fungicide without that double effect that Brown, of New York State39。s name(B) What makes the sea cucumber unusual(C) How to identify the sea cucumber(D) Places where the sea cucumber can be found9. In line 3, the word bizarre is closest in meaning to(A) odd(B) marine(C) simple(D) rare10. According to the Passage, why is the shape of sea cucumbers important?(A) It helps them to digest their food.(B) It helps them to protect themselves from danger.(C) It makes it easier for them to move through the mud.(D) It makes them attractive to fish.11. The words this faculty in line 20 refer to the sea cucumber39。 it will do the same if the surrounding water temperature is too high or if the water bees too polluted.8. What does the passage mainly discuss?(A) The reason for the sea cucumber39。s bloodExample two: (沒講)Elizabeth Hazen and Rachel Brown copatented one of the most widely acclaimed wonder drugs of the postSecond World War years. Hazen and Brown39。s cow pasture in Fauquier County. Virginia, that, when tested, revealed the presence of the microorganisms, In farm owner Nourse39。C, so even food in cold storage may not be pletely safe from them. On the other hand, fungi bring about the deposition of dead organic matter, thus enriching the soil and returning carbon dioxide to the atmosphere. They also enter into a number of mutually beneficial relationships with plants and other (25) organisms. In addition, fungi are the source of many of the most potent antibiotics used in clinical medicine, including penicillin. 11. What does paragraph 1 mainly discuss?(A) Differences between simply and plex fungi(B) Functions of chlorophyll in plants(C) Functions of sugar in the walls of fungal cells(D) Differences between fungi and plants12. Which of the following is mentioned as a major change in how scientists approach the study of fungi?(A) Fungi are no longer classified as plants.(B) Some singlecell organisms are no longer classified as fungi.(C) New methods of species identification have been introduced.(D) Theories about the chemical position of fungi have been revised.13. The word principal in line 5 is closest in meaning to (A) true(B) main(C) logical(D) obvious14. According to the passage, how do fungi obtain carbohydrates?(A) They absorb carbohydrates from their own cell walls.(B) They synthesize chlorophyll to produce carbohydrates.(C) They produce carbohydrates by breaking down chitin.(D) They acquire carbohydrates from other organic matter, both living and dead.15. The passage mentions shrimps, spiders, and insects in line 10 because their skeletons(A) can be destroyed by fungi (B) have unusual chemical positions(C) contain a material found in the walls of fungal cells(D) secrete the same enzymes as the walls of fungal cells do16. Which of the following terms is defined in the passage?(A) chlorophyll (l