首页
登录
职称英语
A pilot cannot fly a plane by sight alone. In many conditions, such as flyin
A pilot cannot fly a plane by sight alone. In many conditions, such as flyin
游客
2025-02-02
10
管理
问题
A pilot cannot fly a plane by sight alone. In many conditions, such as flying at night and landing in dense fog, a pilot must use radar, an alternative way of navigating. Since human eyes are not very good at determining speeds of approaching objects, radar can show a pilot how fast nearby planes are moving. The basic principle of radar is exemplified by what happens when one shouts in a cave. The echo of the sounds against the walls helps a person determine the size of the cave. With radar, however, the waves are radio waves instead of sound waves. Radio waves travel at the speed of light, about 300, 000 kilometers in one second. A radar set sends out a short burst of radio waves: Then it receives the echoes produced when the waves bounce off objects. By determining the time it takes for the echoes to return to the radar set, a trained technician can determine the distance between the radar set and other objects. The word "radar," in fact, gets its name from the term "radio detection and ranging." "Ranging" is the term for detection of the distance between an object and the radar set. Besides being of critical importance to pilots, radar is essential for air traffic control, tracking ships at sea, and for tracking weather systems and storms. [br] According to the passage, what can a radar detect besides location of objects?
选项
A、Size.
B、Weight.
C、Speed.
D、Shape
答案
C
解析
细节题型见本文第三行:Since human eyes are not very good at determining speeds of approaching objects, radar can show a pilot how fast nearby planes are moving. (由于人眼并不擅长判定物体接近的速度,雷达就被用来给飞行员显示附近的飞机速度有多快);因此可知雷达除了可探测物体的方位,还能探测物体的速度,选项C为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3939643.html
相关试题推荐
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Youcannotsaythatthedesireformaterialadvantageisthebasicmotiveinhum
Thoughtheimitationjewelrycanfoolmanypeople,theycannot______uptoanexp
Hecannotseeanythingwithouthisglasses,sohemadea______ofrememberingto
Somemedicalconditionscanoftencurethemselves______,withoutmedicalinterve
随机试题
Whydoesthewritermention"athief"inthefirstparagraph?[br]Bysaying"No
[originaltext]M:Hi,Helen,whatdoyouthinkofourclassinchildren’slitera
Forthispart,youareallowed30minutestowriteanessaycommentingonth
不参与Ⅲ型超敏反应的物质是A.IgG、IgM B.补体 C.IgE D.中
教学《面朝大海,春暖花开》,在初步了解诗歌主要内容后,有学生举手说“老师,我读到
最能反映雌激素水平的是A.底层细胞B.中层细胞C.表层细胞D.纤毛柱状细胞E.子
以下属于“S-O-R行为表达式”构成要素的是A:环境 B:感知 C:刺激
原工商管理、商业经济合并为工商管理专业,教材暂未出,题库内习题为预习使用,教材出
有关气道高反应性(AHR)的描述正确的是A.AHR是哮喘发病的重要神经机制 B
建设工程定额可以按照不同的原则和方法对其进行科学的分类。行业定额是按()分类。
最新回复
(
0
)