Problem: Please answer a question about the following article about Elizabeth II:
From 21 April 1944 until her accession, Elizabeth's arms consisted of a lozenge bearing the royal coat of arms of the United Kingdom differenced with a label of three points argent, the centre point bearing a Tudor rose and the first and third a cross of St George. Upon her accession, she inherited the various arms her father held as sovereign. The Queen also possesses royal standards and personal flags for use in the United Kingdom, Canada, Australia, New Zealand, Jamaica, Barbados, and elsewhere.
When did Elizabeth start to bear a coat of royal arms?
A: 21 April 1944
Problem: Please answer a question about the following article about Apollo:
The earth deity had power over the ghostly world, and it is believed that she was the deity behind the oracle. The older tales mentioned two dragons who were perhaps intentionally conflated. A female dragon named Delphyne (δελφύς, "womb"), who is obviously connected with Delphi and Apollo Delphinios, and a male serpent Typhon (τύφειν, "to smoke"), the adversary of Zeus in the Titanomachy, who the narrators confused with Python. Python was the good daemon (ἀγαθὸς δαίμων) of the temple as it appears in Minoan religion, but she was represented as a dragon, as often happens in Northern European folklore as well as in the East.
Who was the adversary of Zeus in the titanomachy?
A: Typhon
Problem: Please answer a question about the following article about Railway electrification system:
On tracks that London Underground share with National Rail third-rail stock (the Bakerloo and District lines both have such sections), the centre rail is connected to the running rails, allowing both types of train to operate, at a compromise voltage of 660 V. Underground trains pass from one section to the other at speed; lineside electrical connections and resistances separate the two types of supply. These routes were originally solely electrified on the four-rail system by the LNWR before National Rail trains were rewired to their standard three-rail system to simplify rolling stock use.
How did it become possible to share the voltage for different types of train?
A: the centre rail is connected to the running rails
Problem: Please answer a question about the following article about Light-emitting diode:
The light from LEDs can be modulated very quickly so they are used extensively in optical fiber and free space optics communications. This includes remote controls, such as for TVs, VCRs, and LED Computers, where infrared LEDs are often used. Opto-isolators use an LED combined with a photodiode or phototransistor to provide a signal path with electrical isolation between two circuits. This is especially useful in medical equipment where the signals from a low-voltage sensor circuit (usually battery-powered) in contact with a living organism must be electrically isolated from any possible electrical failure in a recording or monitoring device operating at potentially dangerous voltages. An optoisolator also allows information to be transferred between circuits not sharing a common ground potential.
Where are LEDs often used?
A:
free space optics communications