航海英语航海英语 60506050 之之-10-10 航海学航海学十 航海学10.1 航海学基本知识2651_ is the distance east or west measured in degrees，minutes and seconds of arc on the equator between the prime meridian and the meridian passing through the place A. Longitude B. Latitude C. Height D. Bearing KEY: A2652_ refers to the angle between true North and the heading line of the ship A. True position B. True meridian C. True course D. True bearing KEY: C2653A gnomonic projection is based on a(n) _. A. plane tangent at one point B. cylinder tangent at the equator C. cone tangent at one parallel D. infinite series of cones tangent at selected parallels KEY: A2654A great circle track provides the maximum saving in distance on _. A. easterly courses in high latitudes B. southerly courses in high latitudes C. westerly courses in low latitudes D. easterly courses in low latitudes that cross the equator KEY: A2655A lateral system buoy displaying a quick light _. A. should be passed close aboard on either side B. indicates that special caution is required C. is used at a channel bifurcation or junction D. is painted with red and white vertical stripes KEY: B2656A light characteristic of composite group flashing indicates that there is a(n) _. A. sharp turn in the channel B. narrowing in the channel at that point C. junction in the channel D. obstruction that must be left to port KEY: C2657A light having characteristics which include color variations is defined as _. A. switching B. alternating C. oscillating D. fluctuating KEY: B2658A light that has a light period shorter than its dark period is described as _. A. flashing B. pulsating C. occulting D. alternating KEY: A2659A lighted preferred-channel buoy may show a _. A. fixed red light B. Morse (A) white light C. composite group-flashing light D. yellow light KEY: C2660A lighthouse can be identified by its _. A. painted color B. light color and phase characteristic C. type of structure D. All of the above KEY: D2661A line of position formed by sighting two charted objects in line is called a(n) _. A. relative bearing B. range line C. track line D. estimated position KEY: B2662A line on the Earth parallel to the equator is a _. A. gnomonic curve B. small circle C. meridian D. great circle KEY: B2663A mid-channel buoy，if lighted，will show a _. A. fixed red light B. Morse (A) white light C. green light D. flashing red light KEY: B2664A nun buoy will _. A. be green in color B. have an even number C. be left to port when entering from seaward D. be cylindrical in shape KEY: B2665A parallel of latitude other than the equator is a _. A. great circle B. loxodromic curve C. small circle D. gnomonic curve KEY: C2666A plane perpendicular to the polar axis will never form what line on the Earths surface? A. Great circle B. Equator C. Small circle D. Meridian KEY: D2667A plane that cuts the Earths surface and passes through the poles will always form _. A. the equator B. a loxodromic curve C. a small circle D. a meridian KEY: D2668A plane that cuts the Earths surface at any angle and passes through the center will always form _. A. the equator B. a great circle C. a small circle D. a meridian KEY: B2669A preferred-channel buoy may be _. A. lettered B. spherical C. showing a white light D. All of the above KEY: A2670A preferred-channel buoy will show a _. A. white light whose characteristic is Morse (A) B. group-occulting white light C. composite group-flashing (2 + 1) white light D. composite group-flashing (2 + 1) red or green light KEY: D2671A red pillar light-buoy，Fl(2) 5s，is to be substituted for the green conical light-buoy close SWof the stranded wreck The above sentence mainly refers to _. A. a red buoy is to be replaced by a green buoy B. a green buoy is to be replaced by a red buoy C. either a red buoy or a green buoy is to be replaced D. neither a red buoy nor a green buoy is to be replaced KEY: B2672A relative bearing is always measured from _. A. true north B. magnetic north C. the vessels beam D. the vessels head KEY: D2673A rock and sand structure extending from the bank of the river toward the channel is known as a _. A. wingdam B. towhead C. cutoff D. landwall KEY: A2674A SEAMARK，I.E. A BUOY，INDICATING THE NORTH，EAST，SOUTH OR WEST FROM A FIXED POINT，E.G. A WRECK is _. A. Entrance buoy B. New buoy C. Port buoy D. Cardinal buoy KEY: D2675A section of the river that is narrower than usual and is often navigable from bank to bank is a _. A. chute B. stabilized channel C. slough D. Cardinal buoy KEY: n2676A special mark (yellow buoy)，if lighted，may exhibit which light rhythm? A. Flashing B. Morse A C. Equal interval D. Occulting KEY: A2677A special purpose buoy shall be _. A. lighted with