All about Lines

Sealing a deal via a written contract usually requires a signature on the ______ line.

"I walk the line" was a 1956 hit for this legendary American singer.

In mathematics, this line is used to indicate an axis of reflection.

In biology, the Wallace Line passes mostly through which archipelago country, denoting different evolutionary origins of fauna on either side?

A synchronized physical activity, accompanied by music.

The Line Islands that straddle both the equator and International Date Line mostly belong to this Pacific country.

"Telephone Line" was a hit 1976 ballad for which English rock band commonly abbreviated to an acronym?

Companies that provide air transport services for traveling passengers and freight.

A suggestive and often provocative compliment intended to spark further interaction with a person of romantic interest

Among sociobiologists and dissident right-wing intellectuals, the oft-mentioned Hajnal Line demarcates an area of Europe unique in its "higher quality" nuptial metrics, bordered in the East by what major city?

The Traveling Wilburys recorded this railway-themed hit song, ironically just before Roy Orbison's death.

A term indicating straight and unimpeded travel to a location. Hint: Insect

In Australia, the Barassi Line separates the part of the country where Australian Rules Football is dominant from the part that prefers to play _____.

"Doing a line" is a slang reference to what activity?

"Line in the Sand" was a 2004 song by what famous heavy metal band (known for having an umlaut in their name)?