Solution & Explanation for TOEFL iBT Reading Practice Test 25 from Delta’s Key to the Next Generation TOEFL Test – Six Practice Tests for the iBT by Nancy Gallagher
1. A Population ecology is.. .concerned.. .with… is paraphrased in …can be studied in population ecology; …not…solely with the human population is paraphrased in Any species of life… (1.7)
2. C A large number of other species competing for food might cause the population of a species to decrease in size. Clues: Factors that decrease populations are… too many competitors for resources…. (1.1)
3. B The number of nests in a given area is an indirect indicator of a population’s density. Clues: …indirect indicators, such as the number of nests…. (1.1)
4. D The distribution pattern of individuals within a population’s geographical boundaries is called population dispersion. Clues: …dispersion, is the pattern of spacing among individuals within the population s geographical boundaries. (1.1)
5. A Range means territory in this context. Clues: …within the population s geographical boundaries; …habitats…; …areas…. (1.4)
6. D Patches means small areas in this context. Clues: …gathered…; clumped under logs…; …swarm in great numbers…; …swim in large schools…. A patch is a small piece or part of something; in this context, it is a small part of a habitat. (1.4)
7. C The referent of their is something that likes the humidity under logs. The clause states that many forest insects are clumped under logs. Logic tells you that their refers to forest insects. (1.3)
8. B The passage does not give territorial disputes as a reason for clumping. All of the other answers are given: Clumping often results from the irregular distribution of resources…; Clumping may also be associated with mating, safety… Crane flies, for example, swarm in great numbers, a behavior that increases mating chances, and some fish swim in large schools so they are less likely to be eaten by predators. (1.2)
9. B Set up means establish in this context. Clues: …uniform distribution is usually caused…by social interactions that set up individual territories for feeding, breeding, or resting. Animals establish territories that result in uniform spacing of individuals. (1.4)
10. A You can infer that birds competing for a place to build their nests would probably result in a uniform dispersion pattern. Clues: In animal populations, uniform distribution is usually caused by competition for some resource or by social interactions that set up individual territories for feeding, breeding, or resting. (1.5)
11. A The author’s purpose is to identify factors affecting population dispersion. Clues: …by emigrating from one area and immigrating to another with more favorable environmental conditions, thus altering the population s dispersion. (1.6)
12. D In the added sentence, For example is a transition that introduces the example of one of the sampling techniques to estimate densities and total population sizes, mentioned in the previous sentence. In the added sentence, they refers to Ecologists in a previous sentence. (1.8)
13. A, B, E Key information: The characteristics of a population are shaped by its size and by the interactions among individuals and between individuals and their environment; An important characteristic of any population is its density; Another important population characteristic, dispersion…; Three possible patterns of dispersion are clumped, uniform, and random; … often results from the irregular distribution of resources…; …may also be associated with mating, safety, or other social behavior; Populations change in size, structure, and distribution as they respond to changes in environmental conditions. Answers (C) and (D) are minor ideas; answer (F) is not mentioned. (1.9)
14. C The author means that many technologies were very influential. Clues: Communication technology influences the ways in which we think about the world. It changes the things we think about…. (1.4)
15. A You can infer that certain advances in technology have greatly changed communication. Clues: Communication technology influences…; It changes…; In the history of communication, there have been many revolutionary technologies…. (1.5)
16. B Writing began to have a major effect on communication when books became available.
Clues: …before books and the printing press, written language was limited…; It was not until books became available that writing made a major impact. (1.1)
17. C The referent of one is something that was handwritten. The subject of the sentence is books. Logic tells you that one refers to book. (1.3)
18. A The printing press opened to large groups of people… is paraphrased in Numerous people had access to… because of the printing press; …a body of information that had previously been confined to the educated few is paraphrased in … books and education…. (1.7)
19. D Proliferation means spread in this context. Clues: The printing press brought books to the common people, increasing the ranks of the literate. The prefix pro- = forward. (1.4)
20. B Signaled means announced in this context. Clues: …significant revolution in communication technology began…; …invention of the telegraph… a new era in communication technology. (1.4)
21. D The electronic era got its name from the fact that technology sent electrical signals along electrical wires. Clues: …the electronic era—so called because the telegraph used electrical signals to carry information along an electrical wire. (1.1)
22. B The passage does not give the computer as an example of electronic media. All of the other answers are given: …the electronic era—so called because the telegraph used electrical signals to carry information along an electrical wire; …movies…radio…. (1.2)
23. C The author’s purpose is to show that both were initially confined to a few users. Clues: As with the earliest handwritten books, radio technology was at first restricted to the educated few…. (1.6)
24. C The added sentence introduces the idea that electronic technologies had an ability to convey a sense of reality. The next sentence develops this idea with the idea that Voices or pictures could create ideas that appeared authentic. (1.8)
25. A, D, G Printing Press: …the printing press in the fifteenth century…; The printing press with movable type made it possible to produce hundreds of copies of a book in a single day; The printing press brought books to the common people, increasing the ranks of the literate.
C, E Electronic Media: The invention of the telegraph in 1843 signaled a new era in communication technology, the electronic era…; Radio was the first mass broadcast medium…; Voices or pictures…. Answers (B) and (F) describe neither the printing press nor electronic media. (1.10)
26. C You can infer that the Icelandic sagas may not be historically accurate. Clues: …historians have long expressed skepticism about their accuracy. (1.5)
27. B Set eyes on means observe in this context. Clues: … discovered…;… did not go ashore…;… the first European to set eyes on the continent of North America. Heijolfsson discovered the continent, but did not go ashore (walk on land). He was the first to see, or observe, North America. (1.4)
28. B Leif Eriksson was probably the first European to step on the continent of North America. Clues: …Eriksson landed in a place he called Stone land, which was probably the rocky, barren Labrador coast of North America. (1.1)
29. A Abundant means numerous in this context. Clues: …Vinland…; …land of abundant vines and wild grapes. Eriksson may have named the place Vinland because there were a lot of vines and grapes there. (1.4)
30. D They established the first European colony in North America at Vinland… is paraphrased in Eriksson s Vinland was the first European colony in North America…; …the precise location of which remains a subject of scholarly dispute to this day is paraphrased in …but scholars still disagree over exactly where it was. (1.7)