2017年02月17日 01:54来源:互联网作者:上海管理员




  Before we discuss this passage I need to provide some basic background information: All passages can be categorized as at least one of the following three categories:informative, persuasive, and narrative. The primarygoal of an informative passage is to provide information; for persuasive passages it is to promote an opinion; for narrative passages it is to tell an interesting story. This passage is an informative passage. Most informative and persuasive passages share identical structures; this is because all authors want to present content, whether information or arguments, in a clear manner so the reader can follow along. This fundamental desire to be understood resultsin predictable and identical structural components for informative and persuasive passages. The first paragraph of this passage is a structural component I call the main topic statement—here the author tells the reader exactly what the passage is about.

  The fossil remains of the first flyingvertebrates, the pterosaurs, have intriguedpaleontologists for morethan two centuries. Howsuch large creatures, which weighed in some cases as much as a piloted hang-glider and had wingspans from 8 to 12 meters, solved the problems of powered flight, and exactly what these creatures were—reptiles or birds—are among the questions scientists have puzzled over.

  The first sentence of the second paragraph is a structuralcomponent I call the sub topic statement—with the subtopic statement the author tells the reader whatthe following section, usually a paragraph, is about. Notice that the second paragraph follows and supports the main topic statement which is the entire first paragraph—this is a fundamental pattern in all communication, where a claim is made or a topic is announced and evidence or more detailed information is then presented. Explicitly identifying this fundamental relationship, which I call the topic-support relationship, in many cases can help the student better understand what the author is trying to say.

  Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing-like membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on all fours, the three short fingers may have been employed for grasping. When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

  It can be inferred from the first sentence that this paragraph compares the structure of birds and bats with the structure of pterosaurs, so in this way it can be understood as a sub-topic statement. The last sentence of the paragraph is also a sub-topic statement, or more accurately a sub-subtopic statement, indicating that the author will now switch to discussing differences instead of similarities. The original passage does not actually endhere, but since this is an excerpt the rest of the passage does not appear. It should be noted that the words “for example” in the third sentence comprise a linking phrase which signals the existence of a topic-support relationship. The second sentence announces the topic and the third sentence provides more detailed information. In this case this pattern occurs within and underneath the sub-topic statement and support structure of the third paragraph.

  The pterosaurs resembled both birds and batsin their overall structure and proportions. [CLAIM] This is not surprising because the design of any flying vertebrate is subject to aerodynamic constraints. [SUPPORT] For example, both pterosaurs and birds have hollow bones, to reduce weight. [CONTRAST] In birds, however, these bones are reinforced more intensely by internal struts.There are many other dissimilarities in their skeletons.


  1.What does the author mean with the word “intrigued” in paragraph 1?






  (The first paragraph is the main topic statement for this passage, but if we look within it, we can see that thefirst sentence and the rest of the paragraph exhibits a topic-support relationship. The word “intrigued” appears in the topic statement, so we can look to the support section to ascertain its meaning. The support section mentions some questions, and states that scientists have “puzzled” over them. It becomes clear, then, that here intrigued means confused and not its usual meaning of interested. The answer is A.)

  2.The passage has answered which of the following questions?

  (A)Who discovered the first pterosaur?

  (B)Which is the shortest finger on the forelimb of a pterosaur?

  (C)How much does a typical hang-glider weigh?

  (D)Which species of bird evolved first?

  (E)Which assertion regarding pterosaurs do scientists agree on?

  (Main topic statements and sub-topic statements, due to the density of information they contain and their positions near the beginning of passages or paragraphs, are naturally emphasized. The student who understands this will recall that answer choice E is mentioned in the subtopic statement for the second paragraph.)

  3.It can be inferred that the author

  (A)disagrees with the claim that pterosaurs are reptiles

  (B)places importance in basing scientific claims on empirical evidence

  (C)has studied pterosaurs for a long time

  (D)is very interested in birds

  (E)is a professor at a university

  (Since subtopic statements are by definition topic statements and are invariably followed by support sections they always exhibit the topic-support relationship. It should be evident that throughout the passage the author provides many facts in the support sections to support assertions made in the topic statements, leading us to answer choice B.)

  4.In the context of the third paragraph, which of the following is true of thelast sentence?

  (A)it is intended to cast doubt on the veracity of the previous sentences

  (B)it supports assertions made previously

  (C)it has a wider perspective than that of the previous sentences

  (D)it signals a change from a discussion of similarities to a discussion ofdifferences

  (E)it is completely unrelated to the previous sentences

  (Notice the word “however” inthe second to last sentence of the third paragraph, indicating a contrast. From this it should be clear that the answer is D.)

  5.Which of the following is the author most likely to discuss next?

  (A)other flying dinosaurs

  (B)evolutionary advantages of flight

  (C)controversies over features of pterosaurs

  (D)the predecessors of modern birds

  (E)the relationship between modern reptiles and pterosaurs

  (In the main topic statement the author hints that he will discuss two topics: How pterosaurs flew and whetherthey are reptiles or birds. The first subtopic is whether pterosaurs are reptiles or birds, and the sub-topic statement is: “Perhaps the least controversial assertion …” So we can infer that he is organizing his passage in order of increasing controversy. This leads us to answer choice C. Notice that we only needed a structural understanding to solve this question.)