QUES: Fused quartz is a glass made from chemically-pure SiO2 (silica). It has excellent thermal shock characteristics, being able to survive immersion in water while red hot. However, its high melting-temperature (1723 C) and viscosity make it difficult to work with. Normally, other substances are added to simplify processing. One is sodium carbonate (Na2CO3, "soda"), which lowers the glass transition temperature. The soda makes the glass water-soluble, which is usually undesirable, so lime (calcium oxide [CaO], generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added to provide for a better chemical durability. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.
What causes glass to dissolve in Na2CO3?

ANS: unanswerable

QUES: The instrument was primarily used in an ensemble setting well into the 1930s, and although the fad died out at the beginning of the 1930s, the instruments that were developed for the orchestra found a new home in bluegrass. The famous Lloyd Loar Master Model from Gibson (1923) was designed to boost the flagging interest in mandolin ensembles, with little success. However, The "Loar" became the defining instrument of bluegrass music when Bill Monroe purchased F-5 S/N 73987 in a Florida barbershop in 1943 and popularized it as his main instrument.
Where did the mandolins find a new home?

ANS: bluegrass

QUES: To prevent piracy of films, the standard drill of film distribution is to have a movie first released through movie theaters (theatrical window), on average approximately 16 and a half weeks, before having it released to Blu-Ray and DVD (entering its video window). During the theatrical window, digital versions of films are often transported in data storage devices by couriers rather than by data transmission. The data can be encrypted, with the key being made to work only at specific times in order to prevent leakage between screens. Coded Anti-Piracy marks can be added to films to identify the source of illegal copies and shut them down. As a result of these measures, the only versions of films available for piracy during the theatrical window are usually "cams" made by video recordings of the movie screens, which are of inferior quality compared to the original film version.
What can be coded to films to find the source of legal copies?

ANS: unanswerable

QUES: The architecture and urbanism of the Classical civilizations such as the Greek and the Roman evolved from civic ideals rather than religious or empirical ones and new building types emerged. Architectural "style" developed in the form of the Classical orders.
What ideals were Greek and Roman Classical architecture not based on?

ANS:
religious or empirical ones