The problem: Answer a question about this article:
BJTs have three terminals, corresponding to the three layers of semiconductoran emitter, a base, and a collector. They are useful in amplifiers because the currents at the emitter and collector are controllable by a relatively small base current. In an npn transistor operating in the active region, the emitterbase junction is forward biased (electrons and holes recombine at the junction), and electrons are injected into the base region. Because the base is narrow, most of these electrons will diffuse into the reverse-biased (electrons and holes are formed at, and move away from the junction) basecollector junction and be swept into the collector; perhaps one-hundredth of the electrons will recombine in the base, which is the dominant mechanism in the base current. By controlling the number of electrons that can leave the base, the number of electrons entering the collector can be controlled. Collector current is approximately (common-emitter current gain) times the base current. It is typically greater than 100 for small-signal transistors but can be smaller in transistors designed for high-power applications.
How can one find the amount of collector current?
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The answer: (common-emitter current gain) times the base current

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His biography of Anthony the Great entitled Life of Antony( , Vita Antonii) became his most widely-read work. Translated into several languages, it played an important role in the spreading of the ascetic ideal in Eastern and Western Christianity. Depicting Anthony as an illiterate and holy man who through his existence in a primordial landscape has an absolute connection to the divine truth, the biography also resembles the life of his biographer Athanasius. It later served as an inspiration to Christian monastics in both the East and the West. The so-called Athanasian Creed dates from well after Athanasius's death and draws upon the phraseology of Augustine's De trinitate.
Why was this work considered to be important?
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The answer: spreading of the ascetic ideal in Eastern and Western Christianity

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Meanwhile, in January 1968, Nasser commenced the War of Attrition to reclaim territory captured by Israel, ordering attacks against Israeli positions east of the then-blockaded Suez Canal. In March, Nasser offered Yasser Arafat's Fatah movement arms and funds after their performance against Israeli forces in the Battle of Karameh that month. He also advised Arafat to think of peace with Israel and the establishment of a Palestinian state comprising the West Bank and the Gaza Strip. Nasser effectively ceded his leadership of the "Palestine issue" to Arafat.
In what battle had the Fatah movement distinguished itself?
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The answer: Battle of Karameh

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In-mid 2015, China started the build-up of the third generation BeiDou system (BDS-3) in the global coverage constellation. The first BDS-3 satellite was launched 30 September 2015. As of March 2016, 4 BDS-3 in-orbit validation satellites have been launched.
When did China begin constructing the third BeiDou system?
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The answer:
mid 2015