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
8
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] Which of the following would most likely be the topic of the next paragraph 1?
选项
A、Other uses of radar.
B、Uses of sonar technology.
C、Other technology used by pilots.
D、A history of flying.
答案
B
解析
推断题型通读全文可见本段开始介绍了飞行员在驾驶飞机时的局限,于是借助于雷达;接着介绍了雷达的工作原理,名字的来源,及其他功用等;由此判断有关介绍雷达的内容已告一段落,下一段应不会再讲雷达的其他功用(排除选项A);本段因是围绕雷达来写,尽管提到雷达对飞行员起到举足轻重的作用,但目的不是向飞行员介绍不同种类的科学技术(排除选项C);本段的目的也不是为了介绍飞行史(排除选项D);因此只有选项B (使用声纳/声波定位仪这一技术)较为可能;声纳与雷达的工作原理近似,但更多用于水中;由此可假定本段讲了在空中和陆地上雷达的功用,下一段可能要讲解水中利用这一原理——声纳的应用;选项B为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3939650.html
相关试题推荐
Icannotthankyouverymuchforyourkindness,Iowemysuccesstoyou.A、soB、t
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Apilotcannotflyaplanebysightalone.Inmanyconditions,suchasflyin
Thetwinsareso______thatIcannottellthemapart.A、alikeB、likelyC、likeD、li
Youcannotsaythatthedesireformaterialadvantageisthebasicmotiveinhum
Icannotthankyouverymuchforyourkindness,Iowemysuccesstoyou.A、soB、t
Somemedicalconditionscanoftencurethemselves______,withoutmedicalinterve
Thefashionableminiskirtcannotresistthebittercoldness.A、withholdB、withsta
随机试题
主动脉瓣狭窄杂音的特点是()A.胸骨右缘第2肋间收缩期喷射性杂音 B.胸骨左缘
A.当X2不变时,X1每变动一个单位Y的平均变动。 B.当X1不变时,X2每变
A.杞菊地黄汤加减 B.小半夏加茯苓汤加减 C.五皮饮合五苓散加减 D.参
小儿头围与胸围两者几乎相等的年龄是A.3个月 B.5个月 C.9个月 D.
请简要阐述教育史上关于教育的起源的三种主张。
在选择绩效考核方法时,如下选项不属于应考虑的因素的是( )。A.工作实用性
2012年底,某制衣厂有一笔服装加工业务被无证个体户屠某以42万元承包,屠
属于桥梁伸缩缝病害原因的有()。A.交通流量偏小 B.将伸缩缝的预埋钢筋
空调系统冷凝水管道宜采用的管材为()。A.聚氯乙烯塑料管 B.橡胶管
知识点:糖皮质激素 糖皮质激素类药物可明显减少 A.中性粒细胞 B.淋巴细
最新回复
(
0
)