What part of a piano's action permits the keys to be struck in quick repetition?

More Questions:

Who scored both the "Hand of God" goal and the "Goal of the Century" in the same game, during the 1986 World Cup?

Which drug, later found to have devastating side effects, was launched in 1957 to help pregnant women overcome morning sickness?

In NATO's phonetic alphabet, what is the letter "A" referred to as?

What is the NATO phonetic alphabet word for "X"?

What movie character was briefly known as the "Chesapeake Ripper"?

What famous chorus from Verdi's "Il Trovatore" is sung by hammer-wielding Spanish gypsies at dawn?

According to the poem, how many spectators saw Mighty Casey strike out?

What strait separates Spain from Morocco?

Yellowstone National Park protects the wilderness of what mountain chain?

When standing in sunlight, what vitamin does your body synthesize?

Which astronomer gave his name to a telescope launched into space in 1990?

George Lucas" first full feature film, "THX 1138" was released in what year?

Whose tombstone bears the inscription "Everybody Loves Somebody Sometime"?

Who played the title role in the 1984 film “Starman”?

In what decade did the Dust Bowl devastate US Midwest farmers?