_______ magnetism first found a practical use. A: That was in the compass B: It was in the compass that C: It was the compass that D: That was the compass

When the external magnetic field is removed, most or all of the magnetism of soft magnetic materials will not be lost, and the coercivity is very large.

Regarding the magnetism of the complex, the following statement is<br/>incorrect: ( ). A: The magnetism of complexes is one of the important properties of<br/>complexes B: If all substances are placed separately in a magnetic field, they can<br/>be divided into two groups according to their influence by the<br/>magnetic field: diamagnetic, paramagnetic, and ferromagnetic C: Ferromagnetism is a substance, which is strongly attracted by a<br/>magnetic field D: Most of substances are paramagnetic

In the west, the concept of tourist attraction is used to represent the concept of tourist scenic spot. What is the connotation of tourist attractions.（single choice） A: Beautiful B: Quiet C: Magnetism D: Comfort

Arthritis that is relieved by a visit to Magnetic Hill illustrates the fact that A: magnetism has healing properties B: people often deceive themselves C: arthritis is a seasonal thing D: the mind has an effect on the body's health

Permanent magnetism is caused by（）. 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 iro