Questions

The one word substitute for "a person who is always dissatisfied" is malcontent.

When traveling in a vacuum, electronic waves from the electromagnetic spectrum all travel at the same speed. Velocity is speed with direction, so they would all travel at the same velocity, realtively speaking. But frequency and wavelength are quite different.

Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. 

These are actually made to replace floppy disks that were used to store files and programs from the computer.

The format was originally developed to store and play only sound recordings but was later adapted for storage of data (CD-ROM).ese CD's uses Laser technology.

Benjamin Franklin has long been credited with the invention of bifocal lenses and he was the first to wear bifocal lenses. He did not produce them himself but instead had some optician in London or France make them for him to overcome Presbyopia, a condition that Franklin suffered. He was tired switching between lenses for far and near sightedness. And that resulted in inventing Bifocal Lenses.

Brooks Koepka shot a final round 68 for 281 (+1) to win his second straight U.S. Open, one stroke ahead of runner-up Tommy Fleetwood, who closed with the sixth round of 63 in U.S. Open history.