GRE阅读高频机经原文及试题：蝙蝠的回声定位

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GRE阅读高频机经原文及试题：蝙蝠的回声定位

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阅读词汇精选之皱褶

corrugate　v.(使)起波浪形，起皱纹

corrugation　n.波浪形状，起皱纹

crease　n.折缝，· 皱痕

crinkle　v.(使)变皱，· n.皱纹

crumple　v.弄皱，· 扭弯

furrow　n.犁沟，· 皱纹

pucker　v.起皱n.皱褶

ruck　n.皱褶，· 普通群众，· 大量

ruffle　v.变皱，· 弄皱，· 激怒

rumple　v.弄皱，· 弄乱

shrivel　v.枯萎，· 皱缩

wizened　adj.干皱的，· 干巴巴的

wrinkle　n.皱纹，· 窍门

pursy　adj.　皱起的

pleat　n.(衣服· 上的)褶

tuck　v.　卷起，· 隐藏　n.　缝褶，· 活力

hem　n.(衣服· 或裙子的)褶边

懊悔

compunction　n.懊悔，良心不安

contrite　adj.悔罪的，痛悔的

contrition　n.悔罪，痛悔

lamentable　adj.令人惋惜的，悔恨的

penitent　adj.后悔的，忏悔的

impenitent　adj.不悔悟的

remorse　n.懊悔，悔恨

repent　v.懊悔，后悔

repentance　n.悔恨

repentant　adj.对…感到悔恨的

rue　n.后悔，遗憾.

rueful　adj.后悔的，· 遗憾的

guilt　n.罪行，· 内疚

GRE阅读词汇精选之栅栏,窝巢

banister　n.(楼梯的)栏杆

barricade　v.n.设栅阻挡,栅栏

coop　n.(鸡、)笼、栏

corral　n.(牛、马等)畜栏

fold　n.羊栏，· 畜栏，· v.折叠

byre　n　牛栏，· 牛棚

grille　n.(银行，· 邮局柜台上的)铁栅

hurdle　n.跳栏，· 障碍

palings　n.篱笆，· 木栅栏

pen　n.围栏，· 监禁

rail　n.栏杆，· 铁轨，· v.咒骂，猛烈指责

stockade　n.栅栏，· 围栏

palisade　n　篱笆，· 栅栏

aviary　n.大鸟笼,鸟舍·

apiary　n.　养蜂场

hive　n.蜂房，· 忙碌之地

kennel　n.狗舍，· 狗窝

lair　n.野兽的巢穴，· 躲藏处

roost　v.n.栖息，· 鸟巢

nidus　n　巢，· 孵卵所

-沼泽,困境

marsh　n.沼泽地，湿地

mire　n.泥沼，困境

morass　n.沼泽地，困境　　v.陷入困境

quagmire　n.沼泽地，困境

bog　n.　泥塘,沼泽

dismal　a.　阴沉的,凄凉的,暗的　n.低落的情绪,沼泽

swamp　n　沼泽,湿地

dilemma　n.困境，左右为难

hot　water　n.困境

predicament　n.困境,穷境

strand　v　使搁浅,使陷于困境

straits　n.困难，窘境

plight　n.境况,誓约,困境　v.宣誓,保证,约定

GRE词汇词根：aunt

daunt　v.使胆怯，使畏缩

dauntless　adj.勇敢的，无畏的

undaunted　adj.不屈不挠的，无畏的

flaunt　v.炫耀，张扬

gaunt　adj.憔悴的，瘦削的

haunt　v.常到，(鬼魂)出没。(事情)萦绕心头　n.常去的地方

haunting　adj.不易忘怀的

jaunt　v.短程旅游

jaunty　adj.愉快的，满足的

taunt　v.嘲笑，讥笑

vaunt　v.吹嘘，炫耀

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