GRE阅读高频机经原文及试题：蝙蝠的回声定位

　　33. 蝙蝠的回声定位

　　Echolocating bats emit sounds in patterns—characteristic of each species—that contain both frequency-modulated (FM) and constant-frequency (CF) signals. The broadband FM signals and the narrowband CF signals travel out to a target, reflect from it, and return to the hunting bat. In this process of transmission and reflection, the sounds are changed, and the changes in the echoes enable the bat to perceive features of the target.

　　The FM signals report information about target characteristics that modify the timing and the fine frequency structure, or spectrum, of echoes—for example, the target’s size, shape, texture, surface structure, and direction in space. Because of their narrow bandwidth, CF signals portray only the target’s presence and, in the case of some bat species, its motion relative to the bat’s. Responding to changes in the CF echo’s frequency, bats of some species correct in flight for the direction and velocity of their moving prey.

　　33.1. According to the passage, the information provided to the bat by CF echoes differs from that provided by FM echoes in which of the following ways?

　　(A) Only CF echoes alert the bat to moving targets.

　　(B) Only CF echoes identify the range of widely spaced targets.

　　(C) Only CF echoes report the target’s presence to the bat.

　　(D) In some species, CF echoes enable the bat to judge whether it is closing in on its target.

　　(E) In some species, CF echoes enable the bat to discriminate the size of its target and the direction in which the target is moving.

　　33.2. According to the passage, the configuration of the target is reported to the echolocating bat by changes in the

　　(A) echo spectrum of CF signals

　　(B) echo spectrum of FM signals

　　(C) direction and velocity of the FM echoes

　　(D) delay between transmission and reflection of the CF signals

　　(E) relative frequencies of the FM and the CF echoes

　　33.3. The author presents the information concerning bat sonar in a manner that could be best described as

　　(A) argumentative

　　(B) commendatory

　　(C) critical

　　(D) disbelieving

　　(E) objective

　　33.4. Which of the following best describes the organization of the passage?

　　(A) A fact is stated, a process is outlined, and specific details of the process are described.

　　(B) A fact is stated, and examples suggesting that a distinction needs correction are considered.

　　(C) A fact is stated, a theory is presented to explain that fact, and additional facts are introduced to validate the theory.

　　(D) A fact is stated, and two theories are compared in light of their explanations of this fact.

　　(E) A fact is stated, a process is described, and examples of still another process are illustrated in detail.

 

GRE阅读高频机经原文及试题：蝙蝠的回声定位的延伸阅读——GRE阅读高分技巧

 

　　1.题目类型固定或所涉及考点为已做标记范畴

　　1)问事物之间的关系，定位到同时标记这两个事物的地方。

　　2)问作者态度，定位到有态度词标记的地方。

　　3)问事物的缺陷，直接定位到标记缺陷处。

　　4)问文章大意类的主旨题定位与TS

　　2.题干有特征词的题目

　　1）最高级、比较级、数字、以大写字母开头的专有名词、年代、特殊历史时期、引号、斜体字。

　　2）选项标志词与题干核心词双重定位

　　3）段落定位

这两个GRE高分阅读定位技巧是在总结了众多考生的实际经验的基础上总结出来的，非常具有实用价值。所以希望大家在考试的过程中，能加以应用。