Permanent magnetism is found in（）.

A.operation of electrical equipment and generators on board ship
B.the earth's magnetic field affecting the ship's hard iron during construction
C.the horizontal component of the earth's magnetic field acting on the horizontal soft iron
D.the vertical component of the earth's magnetic field acting on the vertical soft iron

A.Appendicitis
B.Cholera
C.Plague
D.Typhus fever

A.Jaundice by fever
B.Acute skin rash or eruption with or without fever
C.Duodenitis