QUES: Glass is in widespread use largely due to the production of glass compositions that are transparent to visible light. In contrast, polycrystalline materials do not generally transmit visible light. The individual crystallites may be transparent, but their facets (grain boundaries) reflect or scatter light resulting in diffuse reflection. Glass does not contain the internal subdivisions associated with grain boundaries in polycrystals and hence does not scatter light in the same manner as a polycrystalline material. The surface of a glass is often smooth since during glass formation the molecules of the supercooled liquid are not forced to dispose in rigid crystal geometries and can follow surface tension, which imposes a microscopically smooth surface. These properties, which give glass its clearness, can be retained even if glass is partially light-absorbingi.e., colored.

What, in contrast to glass, doesn't let light pass through?
What is the answer?
ANS: polycrystalline materials
QUES: Minute Maid Park (home of the Astros) and Toyota Center (home of the Rockets), are located in downtown Houston. Houston has the NFL's first retractable-roof stadium with natural grass, NRG Stadium (home of the Texans). Minute Maid Park is also a retractable-roof stadium. Toyota Center also has the largest screen for an indoor arena in the United States built to coincide with the arena's hosting of the 2013 NBA All-Star Game. BBVA Compass Stadium is a soccer-specific stadium for the Dynamo, the Texas Southern University football team, and Dash, located in East Downtown. In addition, NRG Astrodome was the first indoor stadium in the world, built in 1965. Other sports facilities include Hofheinz Pavilion (Houston Cougars basketball), Rice Stadium (Rice Owls football), and Reliant Arena. TDECU Stadium is where the University of Houston Houston Cougars football team plays. Houston has hosted several major sports events: the 1968, 1986 and 2004 Major League Baseball All-Star Games; the 1989, 2006 and 2013 NBA All-Star Games; Super Bowl VIII and Super Bowl XXXVIII, as well as hosting the 2005 World Series and 1981, 1986, 1994 and 1995 NBA Finals, winning the latter two. Super Bowl LI is currently slated to be hosted in NRG Stadium in 2017.

Which stadium is located in east downtown in Texas?
What is the answer?
ANS: unanswerable
QUES: Many other databases have application software that accesses the database on behalf of end-users, without exposing the DBMS interface directly. Application programmers may use a wire protocol directly, or more likely through an application programming interface. Database designers and database administrators interact with the DBMS through dedicated interfaces to build and maintain the applications' databases, and thus need some more knowledge and understanding about how DBMSs operate and the DBMSs' external interfaces and tuning parameters.

How are many databases accessed?
What is the answer?
ANS:
application software