Misc: the music for advertisements is also called a _____?

Questions

In law, the criminal offense of marrying while one is still a partner in a valid earlier marriage.?

In military terms, what is the opposite of "advance"?

In one of donald horne's novels, who was 'the lucky country?

In physics and engineering, the property of a body that causes it to return to its original position or motion as a result of the action of the so-called restoring forces, or torques, once the body has been disturbed from a condition of equilibrium.?

In physics, process of reduction of matter into a denser form, as in the liquefaction of vapor or steam.?