托福阅读练习1.docx

1、托福阅读练习1Example one: Certainly no creature in the sea is odder than the common sea cucumber. All livingcreature, especially human beings, have their peculiarities, but everything about thelittle sea cucumber seems unusual. What else can be said about a bizarre animal that,Line among other eccentricit

2、ies, eats mud, feeds almost continuously day and night but can(5) live without eating for long periods, and can be poisonous but is considered supremelyedible by gourmets?For some fifty million years, despite all its eccentricities, the sea cucumber hassubsisted on its diet of mud. It is adaptable e

3、nough to live attached to rocks by its tubefeet, under rocks in shallow water, or on the surface of mud flats. Common in cool(10) water on both Atlantic and Pacific shores, it has the ability to suck up mud or sand anddigest whatever nutrients are present.Sea cucumbers come in a variety of colors, r

4、anging from black to reddish-brown tosand-color and nearly white. One form even has vivid purple tentacles. Usually thecreatures are cucumber-shaped-hence their name-and because they are typically(15) rock inhabitants, this shape, combined with flexibility, enables them to squeezeinto crevices where

5、 they are safe from predators and ocean currents.Although they have voracious appetites, eating day and night, sea cucumbers havethe capacity to become quiescent and live at a low metabolic rate-feeding sparinglyor not at all for long periods, so that the marine organisms that provide their food hav

6、e(20) a chance to multiply. If it were not for this faculty, they would devour all the foodavailable in a short time and would probably starve themselves out of existence.But the most spectacular thing about the sea cucumber is the way it defends itself.Its major enemies are fish and crabs, when att

7、acked, it squirts all its internal organsinto the water. It also casts off attached structures such as tentacles. The sea cucumber(25) will eviscerate and regenerate itself if it is attacked or even touched; it will do the sameif the surrounding water temperature is too high or if the water becomes

8、too polluted.8. What does the passage mainly discuss?(A) The reason for the sea cucumbers 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)

9、 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

10、 refer to the sea cucumbers ability to(A) squeeze into crevices(B) devour all available food in a short time(C) suck up mud or sand(D) live at a low metabolic rate12. The fourth paragraph of the passage primarily discusses(A) the reproduction of sea cucumbers(B) the food sources of sea cucumbers (C)

11、 the eating habits of sea cucumbers(D) threats to sea cucumbers existence13. The phrase casts off in line 24 is closest in meaning to(A) grows again(B) grabs(C) gets rid of(D) uses as a weapon14. Of all the characteristics of the sea cucumber, which of the following seems to fascinate the author mos

12、t?(A) What it does when threatened(B) Where it lives(C) How it hides from predators(D) What it eats15. Compared with other sea creatures the sea cucumber is very(A) dangerous(B) intelligent(C) strange(D) fat16. What can be inferred about the defense mechanisms of the sea cucumber?(A) They are very s

13、ensitive to surrounding stimuli.(B) They are almost useless.(C) They require group cooperation.(D) They are similar to those of most sea creatures.17. Which of the following would NOT cause a sea cucumber to release its internal organs into the water?(A) A touch(B) Food(C) Unusually warm water(D) Po

14、llution18. Which of the following is an example of behavior comparable with the sea cucumber living at a low metabolic rate?(A) An octopus defending itself with its tentacles(B) A bear hibernating in the winter(C) A pig eating constantly(D) A parasite living on its hosts bloodExample two: (没讲)Elizab

15、eth Hazen and Rachel Brown copatented one of the most widely acclaimedwonder drugs of the post-Second World War years. Hazen and Browns 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 fo

16、r 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

17、 York States Department of Health in New York, began their Hazen, senior microbiologist at the Department of Health in Laboratories at Albany, and10) long-distance collaboration. Based upon Hazens previous research at Columbia University, where she had built an impressive collection of fungus cultur

18、es, both wereconvinced that an antifungal organism already existed in certain soils. They divided the work. Hazen methodically screened and cultured scores of soil samples, which she then sent to her partner, who prepared extracts, isolated and15) purified active agents, and shipped them back to New

19、 York, where Hazen could studytheir biological properties. On a 1948 vacation. Hazen fortuitously collected a clump of soil from the edge of W. B. Nourses cow pasture in Fauquier County. Virginia, that,when tested, revealed the presence of the microorganisms, In farm owner Nourses honor, Hazen named

20、 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 rena

21、med 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 come from rather modest beginnings.45. What is the main topic of the passage?(A) The

22、 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

23、developed the Second World War. (D) One of the by-products 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

24、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 m

25、icrobiologist (B) A teacher of Hazens(C) A collector of fungi(D) A farmer Example three: (没讲)Fungi, of which there are over 100,000 species, including yeasts and othersingle-celled organisms as well as the common molds and mushrooms, were formerly classified as members of the plant kingdom. However,

26、 in reality they are Line very different from plants and today they are placed in a separate group altogether.(5) The principal reason for this is that none of them possesses chlorophyll, and since they cannot synthesize their own carbohydrates, they obtain their supplies either from the breakdown o

27、f dead organic matter or from other living organisms.Furthermore the walls of fungal cells are not made of cellulose, as those of plantsare, but of another complex sugarlike polymer called chitin, the material from which(10) the hard outer skeletons of shrimps, spiders, and insects are made. The dif

28、ference between the chemical composition of the cell walls of fungi and those of plants is of enormous importance because it enables the tips of the growing hyphae, the threadlike cells of the fungus, to secrete enzymes that break down the walls of plant cells without having any effect on those of t

29、he fungus itself. It is these cellulose-(15) destroying enzymes that enable fungi to attack anything made from wood, wood pulp, cotton, flax, or other plant material.The destructive power of fungi is impressive. They are a major cause of structuraldamage to building timbers, a cause of disease in an

30、imals and humans, and one of the greatest causes of agricultural losses. Entire crops can be wiped out by fungal (20) attacks both before and after harvesting. Some fungi can grow at +50C, whileothers can grow at -5C, so even food in cold storage may not be completely safe from them. On the other ha

31、nd, fungi bring about the decomposition of dead organic matter, thus enriching the soil and returning carbon dioxide to the atmosphere. Theyalso 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 complex fungi(B) Functions of chlorophyll in plants(C) Functions of sugar in the walls of fungal cells(D) Differences between fungi and plants