Problem: High-definition television:

The British high-definition TV service started trials in August 1936 and a regular service on 2 November 1936 using both the (mechanical) Baird 240 line sequential scan (later to be inaccurately rechristened 'progressive') and the (electronic) Marconi-EMI 405 line interlaced systems. The Baird system was discontinued in February 1937. In 1938 France followed with their own 441-line system, variants of which were also used by a number of other countries. The US NTSC 525-line system joined in 1941. In 1949 France introduced an even higher-resolution standard at 819 lines, a system that should have been high definition even by today's standards, but was monochrome only and the technical limitations of the time prevented it from achieving the definition of which it should have been capable. All of these systems used interlacing and a 4:3 aspect ratio except the 240-line system which was progressive (actually described at the time by the technically correct term "sequential") and the 405-line system which started as 5:4 and later changed to 4:3. The 405-line system adopted the (at that time) revolutionary idea of interlaced scanning to overcome the flicker problem of the 240-line with its 25 Hz frame rate. The 240-line system could have doubled its frame rate but this would have meant that the transmitted signal would have doubled in bandwidth, an unacceptable option as the video baseband bandwidth was required to be not more than 3 MHz.

Which system used interlaced scanning to correct the flicker problem of the 940-line?
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A: unanswerable


Problem: Eritrea:

It is estimated that there are around 100 elephants left in Eritrea, the most northerly of East Africa's elephants. The endangered African wild dog (Lycaon pictus) was previously found in Eritrea, but is now deemed extirpated from the entire country. In Gash Barka, deadly snakes like saw-scaled viper are common. Puff adder and red spitting cobra are widespread and can be found even in the highlands.In the coastal areas marine species that are common include dolphin, dugong, whale shark, turtles, marlin/swordfish, and manta ray.

What rare marine species can be found in the coastal areas of Eritrea?
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A: unanswerable


Problem: Carnival:

Carnival was introduced by Portuguese settlers. The celebration is celebrated on each of the archipelago's nine inhabited islands. In Mindelo, São Vicente groups challenge each other for a yearly prize. It has imported various Brazilian carnival traditions. The celebration in SãoNicolau is more traditional, where established groups parade through the Ribeira Brava, gathering in the town square, although it has adopted drums, floats and costumes from Brazil. In São Nicolau three groups, Copa Cabana, Estrela Azul and Brilho Da Zona constructs a painted float using fire, newspaper for the mold, iron and steel to for structure. Carnival São Nicolau is celebrated over three days: dawn Saturday, Sunday afternoon, and Tuesday.

What nationality were the settlers from who introduced Carnival?
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A: Portuguese


Problem: To Kill a Mockingbird:

Tom Robinson is the chief example among several innocents destroyed carelessly or deliberately throughout the novel. However, scholar Christopher Metress connects the mockingbird to Boo Radley: "Instead of wanting to exploit Boo for her own fun (as she does in the beginning of the novel by putting on gothic plays about his history), Scout comes to see him as a 'mockingbird'—that is, as someone with an inner goodness that must be cherished." The last pages of the book illustrate this as Scout relates the moral of a story Atticus has been reading to her, and in allusions to both Boo Radley and Tom Robinson states about a character who was misunderstood, "when they finally saw him, why he hadn't done any of those things ... Atticus, he was real nice," to which he responds, "Most people are, Scout, when you finally see them."

Who is the main example of an innocent destroyed in the novel?
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A:
Tom Robinson