Coral atolls，or a chain of islands at right angles to the radar beam，may show as a long line rather than as individual targets due to ______.A.the effects of beam widthB.limitations on range resolutionC.the pulse length of the radarD.the multiple-target r

题目

Coral atolls，or a chain of islands at right angles to the radar beam，may show as a long line rather than as individual targets due to ______.

A.the effects of beam width

B.limitations on range resolution

C.the pulse length of the radar

D.the multiple-target resolution factor

相似考题

1.The 10-cm radar as compared to a 3-cm radar of similar specifications will ______.A.be more suitable for river and harbor navigationB.provide better range performance on low lying targets during good weather and calm seasC.have a wider horizontal beam widthD.have more sea return during rough sea conditions

2.Cross curves of stability show which of the following？A.The righting arms at various angles of inclination and displacementB.The metacentric height at large angles of heelC.The height of the center of buoyancy at various anglesD.The metacentric radius at various displacements

3.Uncharted lights and radar beacon transmissions may be ________ near the station．A.encounteredB.metC.contactedD.seen

4.The closest point of approach ( CPA ) of a contact on a relative motion radar may be determined ______.A.immediately when the contact is noted on radarB.only if the radar scope is watched constantlyC.after the contact has been marked at least twiceD.by an occasional glance at the radar

参考答案和解析
正确答案：A
更多“Coral atolls,or a chain of islands at right angles to the radar beam,may show as a long li ”相关问题

  • 第1题：

    “AMIDSHIPS ” refers to______.

    A.Back of the vessel

    B.The middle portion of a ship

    C.A backward movement of a vessel

    D.Across the ship, at right angles to the fore-and-aft centerline


    正确答案：B

  • 第2题：

    ______of a radar is governed by the horizontal beam width of the scanner which depends to a great extent on its physical size．

    A.Range discrimination

    B.Bearing discrimination

    C.Echo discrimination

    D.Target discrimination


    正确答案：B
    雷达方位的识别是扫描物体的实际尺度在很大程度上取决于水平波束的宽度。

  • 第3题：

    共用题干
    Caribbean Islands

    What would you see if you took a cruise to the Caribbean Islands?Palm trees and
    coconuts（椰子）?White beaches and clear, blue ocean? Colorful corals（珊瑚）and even
    more colorful fishes and birds?
    You bet.There are thousands of islands in the Caribbean Sea.They are famous for
    their warm,tropical climate and great natural beauty.
    The Caribbean Islands form a chain that separates the Caribbean Sea from the rest of
    the Atlantic Ocean._________(1)Many of the islands were formed by the eruption
    （爆发）of ancient volcanoes（火山）.Others are low-lying coral islands that gradually rose from the ocean.
    The Caribbean Islands are known by several names._________(2)The explorer
    Christopher Columbus called the islands the Indies in 1492 because he thought he was near
    the coast of India.Later,Spain and France called the islands the Antilles.
    There are four large islands in the Caribbean Sea._________(3)These four
    islands are often called the Greater Antilles.Together,they account for about 90 per cent
    of the land area of the Caribbean lslands.
    The rest of the Caribbean Islands are much smaller._________(4)You can see
    why pirates such as the famous Blackbeard sailed these waters.There are countless small
    islands to bury treasure or hide on.
    The weather of the Caribbean Sea is almost always warm and sunny.Sandy beaches
    line the coasts of many islands._________(5)Many tourists arrive on cruise ships.

    _________（3）
    A:But life on the Caribbean Islands is not always paradise.
    B:The earliest name used by Europeans is the Indies,later changed to the West Indies.
    C:They're like a long necklace that stretches between North and South America.
    D:They are Cuba,Puerto Rico,Jamaica,and Hispaniola.
    E:This is why millions of tourists visit the islands each year.
    F:Some of these islands are no more than tiny slivers（小片）of exposed coral.

    答案：D
    解析：

  • 第4题：

    The line leading at right angles to the （）(中线) from the forecastle to the shore is called the forward breast line.

    • A、draft
    • B、waterline
    • C、centerline
    • D、abeam

    正确答案:C

  • 第5题：

    单选题
    You are in restricted visibility and hear a fog signal forward of the beam. Nothing appears on your radar screen. You must（）.
    A

    stop your engines

    B

    sound two prolonged blasts of the whistle

    C

    sound the danger signal

    D

    slow to bare steerageway


    正确答案： C
    解析： 暂无解析

  • 第6题：

    单选题
    The 10-cm radar as compared to a 3-cm radar of similar specifications will（）.
    A

    be more suitable for river and harbor navigation

    B

    provide better range performance on low lying targets during good weather and calm seas

    C

    have a wider horizontal beam width

    D

    have more sea return during rough sea conditions


    正确答案： A
    解析： 暂无解析

  • 第7题：

    单选题
    Mariners are reminded that they should proceed in the general direction indicated by the arrows or，if（）a lane，they should do so as nearly as practicable at right angles to it.
    A

    cross

    B

    crossing

    C

    crossed

    D

    crosses


    正确答案： C
    解析： 暂无解析

  • 第8题：

    单选题
    A navigator fixing a vessel’s position by radar （）.
    A

    can use radar information from one object to fix the position

    B

    should never use radar bearings

    C

    should only use radar bearings when the range exceeds the distance to the horizon

    D

    must use information from targets forward of the beam


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    Coral atolls，or a chain of islands at right angles to the radar beam，may show as a long line rather than as individual targets due to （）.
    A

    the effects of beam width

    B

    limitations on range resolution

    C

    the pulse length of the radar

    D

    the multiple-target resolution factor


    正确答案： D
    解析： 暂无解析

  • 第10题：

    单选题
    Flexible hose under pressure in a hydraulic system will （）.
    A

    tend to twist about its long axis

    B

    expand in length and in diameter

    C

    contract in length and expand in diameter

    D

    flex at right angles to the applied pressure


    正确答案： C
    解析： 暂无解析

  • 第11题：

    单选题
    Which statement concerning maneuvering in restricted visibility is FALSE?（）.
    A

    A vessel which cannot avoid a close-quarters situation with a vessel forward of her beam shall reduce her speed to bare steerageway

    B

    A vessel which hears a fog signal forward of her beam shall stop her engines

    C

    A vessel which hears a fog signal forward of the beam shall navigate with caution

    D

    If a vessel determines by radar that a close-quarters situation is developing，she shall take avoiding action in ample time


    正确答案： A
    解析： 暂无解析

  • 第12题：

    单选题
    The distance a vessel moves at right angles to the original course，when a turn of 180°has been completed，is called the（）.
    A

    advance

    B

    pivoting point

    C

    tactical diameter

    D

    kick


    正确答案： B
    解析： 暂无解析

  • 第13题：

    What may NOT be used when securing heavy vehicles aboard Ro-Ro vessels ________．

    A.Chain lever

    B.Turnbuckle

    C.Webbing

    D.Chain


    正确答案：C

  • 第14题：

    共用题干
    Caribbean Islands

    What would you see if you took a cruise to the Caribbean Islands?Palm trees and
    coconuts（椰子）?White beaches and clear, blue ocean? Colortul corals（珊瑚）and even
    more colorlu!fishes and birds?
    You bet.There are thousands of islands in the Caribbean Sea,They are famous for
    their warm,tropical climate and great natural beauty.
    The Caribbean Islands form a chain that separates the Caribbean Sea from the rest of
    the Atlantic Ocean._________(1)Many of the islands were formed by the eruption
    （爆发）of ancient volcanoes（火山）.Others are low-lying coral islands that gradually rose
    from the ocean.
    The Caribbean Islands are known by several names.__________(2)The explorer
    Christopher Columbus called the islands the Indies in 1492 because he thought he was near
    the coast of India.Later,Spain and France called the islands the Antilles.
    There are four large islands in the Caribbean Sea.________(3)These four
    islands are often called the Greater Antilles.Together,they account for about 90 percent of
    the land area of the Caribbean Islands.
    The rest of the Caribbean Islands are much smaller.______(4)You can see
    why pirates such as the famous Blackbeard sailed these waters.There are countless small
    islands to bury treasure or hide on.
    The weather of the Caribbean Sea is almost always warm and sunny.Sandy beaches
    line the coasts of many islands.__________(5)Many tourists arrive on cruise
    ships.

    ________（3）
    A: But life on the Caribbean Islands is not always paradise.
    B:The earliest name used by Europeans is the Indies,later changed to the West Indies.
    C: They're like a long necklace that stretches between North and South America.
    D: They are Cuba,Puerto Rico,Jamaica,and Hispaniola.
    E: This is why millions of tourists visit the islands each year.
    F: Some of these islands are no more than tiny slivers（小片）of exposed coral.

    答案：D
    解析：

  • 第15题：

    下列日常生活用语中，表示电话对话的句子是（）

    AHello, this is Li. May I speak to Chen, please?

    BHold on, please.

    CWould you hold the line, please?

    DWho's calling, please?

    EI'm sorry. I think you have the wrong number.

    FI'm sorry, but Chen is not available to come to the phone right now. May I take a message?


    A,B,C,D,E,F
    略

  • 第16题：

    单选题
    A mooring line leading at nearly right angles to the keel is a（）.
    A

    bow line

    B

    breast line

    C

    spring line

    D

    stern line


    正确答案： B
    解析： 暂无解析

  • 第17题：

    单选题
    You hear the fog signal of another vessel forward of your beam.Risk of collision may exist.You MUST（）.
    A

    Reduce speed to bare steerageway

    B

    Stop your engines

    C

    Begin a radar plot

    D

    All of the above


    正确答案： A
    解析： 暂无解析

  • 第18题：

    单选题
    A structure，usually made of stone，or cement pilings，which extends from the bank at approximately right angles to the current is called a（）.
    A

    dike

    B

    revetment

    C

    cutoff

    D

    crib


    正确答案： A
    解析： 暂无解析

  • 第19题：

    单选题
    It may be found that，in certain circumstances，radar beacon emissions can cause（）with the normal radar display，particularly at close range.
    A

    unwanted interference

    B

    unexpected figures

    C

    abnormal data

    D

    unwanted information


    正确答案： B
    解析： 暂无解析

  • 第20题：

    单选题
    Which one of the following is a counterexample to the statement “If two angles are supplementary, then they are right angles?”
    A

    If two angles are complementary, then they are not right angles.

    B

    If two angles are fight angles, then they are supplementary.

    C

    If two angles are not supplementary, then they are not right angles.

    D

    If two angles are supplementary, then one could measure 100° and one could measure 80°.

    E

    If two angles are not fight angles, then they are not supplementary.


    正确答案： E
    解析：
    A counterexample is an example that proves a statement to be false. Answer D shows one example where angles are supplementary but are not right angles, since one measures 100° and the other measures 80°.

  • 第21题：

    单选题
    Which statement concerning the operation of radar in fog is TRUE?（）
    A

    Radar ranges are less accurate in fog

    B

    Navigation buoys will always show up on radar

    C

    A sandy beach will show up clearer on radar than a rocky cliff

    D

    Small wooden boats may not show up on radar


    正确答案： B
    解析： 暂无解析

  • 第22题：

    单选题
    In any right triangle, the acute angles are ______.
    A

    Equal

    B

    Adjacent angles

    C

    Vertical angles

    D

    Complementary angles

    E

    Supplementary angles


    正确答案： E
    解析：
    Since the right angle measures 90 degrees, the sum of the two acute angles must be 180-90=90 degrees.

  • 第23题：

    单选题
    The closest point of approach (CPA) of a contact on a relative motion radar may be determined（）.
    A

    immediately when the contact is noted on radar

    B

    only if the radar scope is watched constantly

    C

    after the contact has been marked at least twice

    D

    by an occasional glance at the radar


    正确答案： C
    解析： 暂无解析

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