QUES: LaserDiscs potentially had a much longer lifespan than videocassettes. Because the discs were read optically instead of magnetically, no physical contact needs to be made between the player and the disc, except for the player's clamp that holds the disc at its center as it is spun and read. As a result, playback would not wear the information-bearing part of the discs, and properly manufactured LDs would theoretically last beyond one's lifetime. By contrast, a VHS tape held all of its picture and sound information on the tape in a magnetic coating which is in contact with the spinning heads on the head drum, causing progressive wear with each use (though later in VHS's lifespan, engineering improvements allowed tapes to be made and played back without contact). Also, the tape was thin and delicate, and it was easy for a player mechanism, especially on a low quality or malfunctioning model, to mishandle the tape and damage it by creasing it, frilling (stretching) its edges, or even breaking it.

Were Laserdiscs or VHS more durable in the long run?
What is the answer?
ANS: LaserDiscs
QUES: Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.

Which empire ravished the Chengdu region with constant warfare and economic distress?
What is the answer?
ANS: the Tibetan Empire
QUES: The American studies program reflected the worldwide anti-Communist ideological struggle. Norman Holmes Pearson, who worked for the Office of Strategic Studies in London during World War II, returned to Yale and headed the new American studies program, in which scholarship quickly became an instrument of promoting liberty. Popular among undergraduates, the program sought to instruct them in the fundamentals of American civilization and thereby instill a sense of nationalism and national purpose. Also during the 1940s and 1950s, Wyoming millionaire William Robertson Coe made large contributions to the American studies programs at Yale University and at the University of Wyoming. Coe was concerned to celebrate the 'values' of the Western United States in order to meet the "threat of communism."

Why did Coe donate to American studies programs?
What is the answer?
ANS:
to celebrate the 'values' of the Western United States