Input: Read this: Many were surprised by these changes to the CBC schedule, which were apparently intended to attract a younger audience to the network; some suggested they might alienate the core CBC viewership. Another note of criticism was made when the network decided to move The National in some time zones to simulcast the American version of The One over the summer. This later became a moot point, as The One was taken off the air after two weeks after extremely low American and Canadian ratings, and the newscast resumed its regular schedule.
Question: Twice a year, the CBC will retain new talent in order to serve what purpose?

Output: unanswerable


Input: Read this: Malian musical traditions are derived from the griots, who are known as "Keepers of Memories". Malian music is diverse and has several different genres. Some famous Malian influences in music are kora virtuoso musician Toumani Diabaté, the late roots and blues guitarist Ali Farka Touré, the Tuareg band Tinariwen, and several Afro-pop artists such as Salif Keita, the duo Amadou et Mariam, Oumou Sangare, and Habib Koité. Dance also plays a large role in Malian culture. Dance parties are common events among friends, and traditional mask dances are performed at ceremonial events.
Question: What translates to keeper of the songs?

Output: unanswerable


Input: Read this: Another principal tool in the diagnosis of infectious disease is microscopy. Virtually all of the culture techniques discussed above rely, at some point, on microscopic examination for definitive identification of the infectious agent. Microscopy may be carried out with simple instruments, such as the compound light microscope, or with instruments as complex as an electron microscope. Samples obtained from patients may be viewed directly under the light microscope, and can often rapidly lead to identification. Microscopy is often also used in conjunction with biochemical staining techniques, and can be made exquisitely specific when used in combination with antibody based techniques. For example, the use of antibodies made artificially fluorescent (fluorescently labeled antibodies) can be directed to bind to and identify a specific antigens present on a pathogen. A fluorescence microscope is then used to detect fluorescently labeled antibodies bound to internalized antigens within clinical samples or cultured cells. This technique is especially useful in the diagnosis of viral diseases, where the light microscope is incapable of identifying a virus directly.
Question: What is microscopy unnecessary for?

Output: unanswerable


Input: Read this: The British adopted "effective ceiling", meaning the altitude at which a gun could deliver a series of shells against a moving target; this could be constrained by maximum fuse running time as well as the gun's capability. By the late 1930s the British definition was "that height at which a directly approaching target at 400 mph (=643.6 km/h) can be engaged for 20 seconds before the gun reaches 70 degrees elevation". However, effective ceiling for heavy AA guns was affected by non-ballistic factors:
Question: Along with other factors, how long must a target be engaged to have effective ceiling?

Output:
for 20 seconds