Problem: Light-emitting diode:

Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:

What is the most common example of a machine vision system?
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A: Barcode scanners


Problem: The major landmark of puberty for males is the first ejaculation, which occurs, on average, at age 13. For females, it is menarche, the onset of menstruation, which occurs, on average, between ages 12 and 13. The age of menarche is influenced by heredity, but a girl's diet and lifestyle contribute as well. Regardless of genes, a girl must have a certain proportion of body fat to attain menarche. Consequently, girls who have a high-fat diet and who are not physically active begin menstruating earlier, on average, than girls whose diet contains less fat and whose activities involve fat reducing exercise (e.g. ballet and gymnastics). Girls who experience malnutrition or are in societies in which children are expected to perform physical labor also begin menstruating at later ages.
Besides heredity, what other factors contribute to when menustration begins?
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Answer: diet and lifestyle


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
15th Street starts at FDR Drive, and 16th Street starts at a dead end half way between FDR Drive and Avenue C. They are both stopped at Avenue C and continue from First Avenue to West Street, stopped again at Union Square, and 16th Street also pauses at Stuyvesant Square.
Where does 15th Street start?
A: FDR Drive


Context and question: In February 2010 Shell and Cosan formed a 50:50 joint-venture, Raízen, comprising all of Cosan's Brazilian ethanol, energy generation, fuel distribution and sugar activities, and all of Shell's Brazilian retail fuel and aviation distribution businesses. In March 2010, Shell announced the sale of some of its assets, including its liquid petroleum gas (LPG) business, to meet the cost of a planned $28bn capital spending programme. Shell invited buyers to submit indicative bids, due by 22 March, with a plan to raise $2–3bn from the sale. In June 2010, Royal Dutch Shell agreed to acquire all the business of East Resources for a cash consideration of $4.7 billion. The transaction included East Resources' tight gas fields.
Royal Dutch Shell agreed to acquire all the business of what entity in June 2010?
Answer: East Resources


Question: Spielberg's films often deal with several recurring themes. Most of his films deal with ordinary characters searching for or coming in contact with extraordinary beings or finding themselves in extraordinary circumstances. In an AFI interview in August 2000 Spielberg commented on his interest in the possibility of extra terrestrial life and how it has influenced some of his films. Spielberg described himself as feeling like an alien during childhood, and his interest came from his father, a science fiction fan, and his opinion that aliens would not travel light years for conquest, but instead curiosity and sharing of knowledge.
Is there an answer to this question: What do most people think aliens would visit Earth for?

Answer: unanswerable


QUES: Even during the war, Eritrea developed its transportation infrastructure by asphalting new roads, improving its ports, and repairing war-damaged roads and bridges as a part of the Warsay Yika'alo Program. The most significant of these projects was the construction of a coastal highway of more than 500 km connecting Massawa with Asseb, as well as the rehabilitation of the Eritrean Railway. The rail line has been restored between the port of Massawa and the capital Asmara, although services are sporadic. Steam locomotives are sometimes used for groups of enthusiasts.

How many km of war-damaged roads has Eritrea fixed?
What is the answer?
ANS:
unanswerable