Question: The most familiar, and historically the oldest, types of glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. The term glass, in popular usage, is often used to refer only to this type of material, which is familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives. A very clear and durable quartz glass can be made from pure silica, but the high melting point and very narrow glass transition of quartz make glassblowing and hot working difficult. In glasses like soda lime, the compounds added to quartz are used to lower the melting temperature and improve workability, at a cost in the toughness, thermal stability, and optical transmittance.
Is there an answer to this question: Which kinds of glass existed the furthest in the past?

Answer: silicate glasses

Question: Between 1963 and 1965, there was a "downtown boom" that led to the construction of more than 700 buildings in the city. In 1968, Virginia Commonwealth University was created by the merger of the Medical College of Virginia with the Richmond Professional Institute. In 1970, Richmond's borders expanded by an additional 27 square miles (70 km2) on the south. After several years of court cases in which Chesterfield County fought annexation, more than 47,000 people who once were Chesterfield County residents found themselves within the city's perimeters on January 1, 1970. In 1996, still-sore tensions arose amid controversy involved in placing a statue of African American Richmond native and tennis star Arthur Ashe to the famed series of statues of Confederate heroes of the Civil War on Monument Avenue. After several months of controversy, the bronze statue of Ashe was finally completed on Monument Avenue facing the opposite direction from the Confederate Heroes on July 10, 1996.
Is there an answer to this question: About how many structures were built in Richmond during the downtown boom?

Answer: 700

Question: A cappella [a kapplla] (Italian for "in the manner of the chapel") music is specifically group or solo singing without instrumental accompaniment, or a piece intended to be performed in this way. It contrasts with cantata, which is accompanied singing. The term "a cappella" was originally intended to differentiate between Renaissance polyphony and Baroque concertato style. In the 19th century a renewed interest in Renaissance polyphony coupled with an ignorance of the fact that vocal parts were often doubled by instrumentalists led to the term coming to mean unaccompanied vocal music. The term is also used, albeit rarely, as a synonym for alla breve.
Is there an answer to this question: What did cantata origionally differerntiate between?

Answer: unanswerable

Question: Commercial credit and agricultural consumer loans were the main types of loans. The trade credit was usually extended by temples in order to finance trade expeditions and was nominated in silver. The interest rate was set at 1/60 a month (one shekel per mina) some time before 2000 BC and it remained at that level for about two thousand years. Rural loans commonly arose as a result of unpaid obligations due to an institution (such as a temple), in this case the arrears were considered to be lent to the debtor. They were denominated in barley or other crops and the interest rate was typically much higher than for commercial loans and could amount to 1/3 to 1/2 of the loan principal.
Is there an answer to this question: What typically arose as a result of unpaid obligations?

Answer:
Rural loans