How many keys on a piano?

A standard full piano has 88 keys. 52 white or "natural" keys, and 36 black keys, which can be "sharp" or "flat" depending on if the note is high or low. This makes a total of seven full octaves plus a minor third, from A0 to C8

Musically speaking, a sharp is a note that is one half step higher than its natural note. Likewise, a flat is a note that is one half step lower than its natural note.
However, the two terms are also used in general when tuning instruments. If you are sharp you are out of tune on the high side, and if you are flat you are out of tune on the low side.

First Four Minute Mile

In athletics, the four-minute mile refers to the running of a mile in under four minutes.

The first four-minute mile was ran by Roger Bannister on May 6, 1954. He ran it in a time of 3 minutes 59.4 seconds. This historic athletic achievement took place during a meet between British AAA and Oxford University at Iffley Road Track in Oxford. It was watched by about 3,000 spectators.

Currently, the mile record is held by Hicham El Guerroui, who set a time of 3 minutes 43.13 seconds in Rome in 1999.

Oddly enough, no woman has yet to run a four-minute mile, although it is thought to be physically possible. The current women's record holder is Russian Svetlana Masterkova, with a time of 4 minutes 12.56 seconds.

Highest Point in the United States

The highest point anywhere the United States is Mount McKinley, Alaska, measuring in at 20,320 feet (6,194 meters).

The highest point in the lower 48 states is Mount Whitney, California, which comes in at 14,505 feet (4,421 meters).

I found a cool map from Geology.com that shows the highest point for each state. Click HERE to see it.