Wordorigins.org

This Americanism, meaning mediocre or of moderate quality, dates to the early 19th century. The following appeared in an ad in the Eastern Argus of Portland, Maine on 23 March 1824:

J. Haskell
Has just received 4 cases prime HATS, new style—also, 4 cases imitation HATS, at $2, “from fair to middling.”

This phrase meaning to accept responsibility, suffer consequences is an Americanism dating to the mid-19th century. The underlying metaphor is uncertain. From the New Hampshire Statesman and State Journal of 17 February 1834:

We want no equivocation—“face the music” this time—Gove and Barton are able backers.

Many of the earliest citations of the phrase are from New Hampshire, indicating that the term arose there, or at least arose in New England.

There are a couple of common explanations for the phrase, but none have any conclusive evidence to support them.  The first explanation is that it derives from the stage. With the musicians in a pit before the stage, to face the music is to turn towards the audience and either their hoots or cheers. Another is that it is military in origin, and refers to a ceremony where an officer is cashiered and is literally drummed out of the service.

Because of the early citations from New Hampshire, it has also been suggested that face the music may have originated in contra dancing, a social dance form that was popular in 19th century New England and is still practiced in New Hampshire today. But like the other proposed explanations, no evidence definitively linking the phrase to the dance form has been unearthed.

(Source: ADS-L)

A dry run is a rehearsal. The term appears to come from American firefighting jargon, where dry denoted a practice where the hoses were not turned on.

Run, meaning a response to a fire alarm, either real or a drill, dates to the late 19th century. The Portland Morning Oregonian of 11 September 1886 contains a use of wet run in reference to a contest between fire companies:

Open to all; wet run; distance, 200 yards to hydrant; lay 350 feet of hose; [...] ; attach pipe and throw water.

This is a rather common American slang phrase. Those who drink the Kool-Aid exhibit unswerving loyalty to and belief in their leaders. This figurative use has been around since the mid-1980s.

Kool-Aid is a brand name for a soft drink mix that is popular among American children, but the allusion is actually a much grimmer one. In 1978, Jim Jones, the leader of the People’s Temple, a San Francisco cult that had recently moved to the jungles of Guyana, ordered his people to commit suicide. 914 cult members died, including 276 children and Jones himself. Most killed themselves by drinking a grape drink laced with cyanide and sedatives. (It may not have actually been Kool-Aid brand that was used, but as the most popular brand that was the name that stuck in the public consciousness.) Most of those who refused to commit suicide were executed, either shot or killed with lethal injection.

Hence, to drink the Kool-Aid is to show cult-like devotion to one’s leaders.

This is a rather etymologically mysterious term to most people today, but an examination of the changes in meaning of drag over the centuries makes it clear why we call racing for fastest acceleration drag racing.

In the 16th century, drag was a term for a sledge, a platform with skids, not wheels, that could be dragged behind a horse or ox. From an act of Elizabeth I of 1576:

Sleades, carres, or drags, furnished for...repairing...high wayes.