Question: "What size tube do Yagi-Uda arrays often use?"  Context: "Instead, it is often desired to have an antenna whose impedance does not vary so greatly over a certain bandwidth. It turns out that the amount of reactance seen at the terminals of a resonant antenna when the frequency is shifted, say, by 5%, depends very much on the diameter of the conductor used. A long thin wire used as a half-wave dipole (or quarter wave monopole) will have a reactance significantly greater than the resistive impedance it has at resonance, leading to a poor match and generally unacceptable performance. Making the element using a tube of a diameter perhaps 1/50 of its length, however, results in a reactance at this altered frequency which is not so great, and a much less serious mismatch which will only modestly damage the antenna's net performance. Thus rather thick tubes are typically used for the solid elements of such antennas, including Yagi-Uda arrays."  Answer:
Ans: tube of a diameter perhaps 1/50 of its length

Question: "what is the last era mentioned?"  Context: "As the Tokugawa period progressed more value became placed on education, and the education of females beginning at a young age became important to families and society as a whole. Marriage criteria began to weigh intelligence and education as desirable attributes in a wife, right along with physical attractiveness. Though many of the texts written for women during the Tokugawa period only pertained to how a woman could become a successful wife and household manager, there were those that undertook the challenge of learning to read, and also tackled philosophical and literary classics. Nearly all women of the samurai class were literate by the end of the Tokugawa period."  Answer:
Ans: Tokugawa period

Question: "How far back does Christianity go in Galicia?"  Context: "Christianity is the most widely practised religion in Galicia, as it has been since its introduction in Late Antiquity, although it lived alongside the old Gallaeci religion for a few centuries. Today about 73% of Galicians identify themselves as Christians. The largest form of Christianity practised in the present day is Catholicism, though only 20% of the population described themselves as active members. The Catholic Church in Galicia has had its primatial seat in Santiago de Compostela since the 12th century."  Answer:
Ans: Late Antiquity

Question: "Who else did Universal's parent company purchase?"  Context: "Matsushita provided a cash infusion, but the clash of cultures was too great to overcome, and five years later Matsushita sold an 80% stake in MCA/Universal to Canadian drinks distributor Seagram for $5.7 billion. Seagram sold off its stake in DuPont to fund this expansion into the entertainment industry. Hoping to build an entertainment empire around Universal, Seagram bought PolyGram in 1999 and other entertainment properties, but the fluctuating profits characteristic of Hollywood were no substitute for the reliable income stream gained from the previously held shares in DuPont."  Answer:
Ans: PolyGram