Q: Extract the answer to the question from the following context. Question: What were Radviolos and Astikai? Context: In the late 14th century, in the Grand Duchy of Lithuania, Vytautas the Great reformed the Grand Duchy's army: instead of calling all men to arms, he created forces comprising professional warriors—bajorai ("nobles"; see the cognate "boyar"). As there were not enough nobles, Vytautas trained suitable men, relieving them of labor on the land and of other duties; for their military service to the Grand Duke, they were granted land that was worked by hired men (veldams). The newly formed noble families generally took up, as their family names, the Lithuanian pagan given names of their ennobled ancestors; this was the case with the Goštautai, Radvilos, Astikai, Kęsgailos and others. These families were granted their coats of arms under the Union of Horodlo (1413).
A: noble families

Q: Extract the answer to the question from the following context. Question: What did the male members of Bell's family have in common? Context: Bell's father, grandfather, and brother had all been associated with work on elocution and speech, and both his mother and wife were deaf, profoundly influencing Bell's life's work. His research on hearing and speech further led him to experiment with hearing devices which eventually culminated in Bell being awarded the first U.S. patent for the telephone in 1876.[N 4] Bell considered his most famous invention an intrusion on his real work as a scientist and refused to have a telephone in his study.[N 5]
A: Bell's father, grandfather, and brother had all been associated with work on elocution and speech

Q: Extract the answer to the question from the following context. Question: What environment is required to form an exciton? Context: The structure of QD-LEDs used for the electrical-excitation scheme is similar to basic design of OLEDs. A layer of quantum dots is sandwiched between layers of electron-transporting and hole-transporting materials. An applied electric field causes electrons and holes to move into the quantum dot layer and recombine forming an exciton that excites a QD. This scheme is commonly studied for quantum dot display. The tunability of emission wavelengths and narrow bandwidth is also beneficial as excitation sources for fluorescence imaging. Fluorescence near-field scanning optical microscopy (NSOM) utilizing an integrated QD-LED has been demonstrated.
A: applied electric field

Q: Extract the answer to the question from the following context. Question: What was common function of electric recordings? Context: Eventually, when it was more common for electric recordings to be played back electrically in the 1930s and 1940s, the overall tone was much like listening to a radio of the era. Magnetic pickups became more common and were better designed as time went on, making it possible to improve the damping of spurious resonances. Crystal pickups were also introduced as lower cost alternatives. The dynamic or moving coil microphone was introduced around 1930 and the velocity or ribbon microphone in 1932. Both of these high quality microphones became widespread in motion picture, radio, recording, and public address applications.
A:
to be played back electrically