对
错
第1题:
If a magnetic compass is not affected by any magnetic field other than the Earth’s which statement is TRUE?______.
A.Compass error and variation are equal
B.Compass north will be true north
C.Variation will equal deviation
D.There will be no compass error
第2题:
第3题:
第4题:
第5题:
第6题:
第7题:
对
错
第8题:
intensifications
justifications
records
correlations
fluctuations
第9题:
we should not worry about the transition of the Earth’s magnetic field
the Earth’s magnetic field will not change for at least 2000 years
the Earth’s magnetic field has decreased its strength rapidly
the transition of the Earth’s magnetic field can be controlled by modern science
第10题:
criterion
orientation
standard
guideline
第11题:
The Flinders bar
The heeling magnet
Quadrantal soft iron spheres
Bar magnets in the binnacle
第12题:
Along the magnetic equator
Connected by the isoclinal line
The isopors
The magnetic poles
第13题:
第14题:
第15题:
第16题:
第17题:
第18题:
begun to change in the opposite direction
been weakening in strength for a long time
caused the changes on the polarities
misguided many a man and animal
第19题:
destroy almost all the creatures on the Earth
cause some species extinctions on the Earth
not be as disastrous as the previous one
cause no big trouble for man and animals
第20题:
the compass will become useless
man and animals will be confused as to directions
the magnetic strength of the Earth will disappear
the magnetic strength of the Earth will be stronger
第21题:
operation of electrical equipment and generators on board ship
the earth's magnetic field affecting the ship's hard iron during construction
the horizontal component of the earth's magnetic field acting on the horizontal soft iron
the vertical component of the earth's magnetic field acting on the vertical soft iron
第22题:
hammering and jarring
vibration and pounding
varying magnetic fields
stable or permanent magnetism of the ship
第23题:
Compass error and variation are equal
Compass north will be true north
Variation will equal deviation
There will be no compass error
第24题:
the flows of melted iron inside the Earth
the periodical movement of the Earth
the mechanical energy of the solar system
the force coming from outer space