33. 蝙蝠的回声定位
Echolocating bats emit sounds in patternscharacteristic of each speciesthat contain both frequency-modulated and constant-frequency 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 echoesfor example, the targets size, shape, texture, surface structure, and direction in space. Because of their narrow bandwidth, CF signals portray only the targets presence and, in the case of some bat species, its motion relative to the bats. Responding to changes in the CF echos 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?
Only CF echoes alert the bat to moving targets.
Only CF echoes identify the range of widely spaced targets.
Only CF echoes report the targets presence to the bat.
In some species, CF echoes enable the bat to judge whether it is closing in on its target.
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
echo spectrum of CF signals
echo spectrum of FM signals
direction and velocity of the FM echoes
delay between transmission and reflection of the CF signals
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
argumentative
commendatory
critical
disbelieving
objective
33.4. Which of the following best describes the organization of the passage?
A fact is stated, a process is outlined, and specific details of the process are described.
A fact is stated, and examples suggesting that a distinction needs correction are considered.
A fact is stated, a theory is presented to explain that fact, and additional facts are introduced to validate the theory.
A fact is stated, and two theories are compared in light of their explanations of this fact.
A fact is stated, a process is described, and examples of still another process are illustrated in detail.
福建省2014高考英语一轮复习 作业手册(13)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(26)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(21)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(22)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 21 Human Biology Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 13 People Word版含解析
福建省2014高考英语一轮复习 作业手册(8)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(15)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(11)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 16 Stories Word版含解析
福建省2014高考英语一轮复习 作业手册(25)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 22 Environmental Protection Word版含解析
福建省2014高考英语一轮复习 作业手册(18)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(19)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(20)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(4)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(28)(含解析)新人教版
福建省2014高考英语一轮复习 作业手册(17)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 18 Beauty Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 15 Learning Word版含解析
福建省2014高考英语一轮复习 作业手册(30)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 24 Society Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 19 Language Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 11 The Media Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 8 Adventure Word版含解析
福建省2014高考英语一轮复习 作业手册(2)(含解析)新人教版
2014北师大版英语一轮复习指导考点针对练 Unit 6 Design Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 9 Wheels Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 14 Careers Word版含解析
2014北师大版英语一轮复习指导考点针对练 Unit 23 Conflict Word版含解析
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |