An isotherm is ______.
A.a line on a weather map connecting equal points of both temperature and pressure
B.an instrument that measures the climatological effects of temperature
C.a line connecting points of equal barometric pressure on a weather map
D.a line connecting points of equal temperature on a weather map
第1题：
Isogonic lines are lines on a chart indicating ______.
A.points of equal variation
B.points of zero variation
C.the magnetic latitude
D.magnetic dip
第2题：
Lines on a chart which connect points of equal magnetic variation are called ______.
A.magnetic latitudes
B.magnetic declinations
C.dip
D.isogonic lines
第3题：
On a weather map, a large letter “H” means ______.
A.a high pressure area with cool, dry air, and fair weather
B.a high pressure area with warm, moist air, and inclement weather
C.horse latitudes, with rough seas and strong winds
D.a heavy squall line near the “H”
第4题：
联络线 connecting line
第5题：
A line connecting all possible positions of your vessel at any given time is a ______.
A.longitude line
B.latitude line
C.line of position
D.Fix
第6题：
What defines a great circle?
A.A curved line drawn on a Mercator Chart
B.A course line that inscribes a loxodromic curve
C.The shortest distance between any two points on the earth
D.The smallest circle that can be drawn on the face of a sphere
第7题：
The line connecting the Loran-C master station with a secondary station is called the ______．
A.Focus line
B.Base line
C.Side line
D.Center line
第8题：
The agonic line on an isomagnetic chart indicates the ______.
A.magnetic equator
B.magnetic longitude reference line
C.points where there is no variation
D.points where there is no annual change in variation
第9题：
A line of position is ______.
A.a line connecting two charted objects
B.a line on some point of which the vessel may be presumed to be located
C.the position of your vessel
D.not used in a running fix
第10题：
（）has three specific points: fixed line and announcing shipping time in advance.