Extract the answer to the question from the following context. Question: Why were 10 giant skeletons required? Context: With filming completed in Rome, production moved to Mexico City in late March to shoot the film's opening sequence, with scenes to include the Day of the Dead festival filmed in and around the Zocalo and the Centro Historico district. The planned scenes required the city square to be closed for filming a sequence involving a fight aboard a Messerschmitt-Bolkow-Blohm Bo 105 helicopter flown by stunt pilot Chuck Aaron, which called for modifications to be made to several buildings to prevent damage. This particular scene in Mexico required 1,500 extras, 10 giant skeletons and 250,000 paper flowers. Reports in the Mexican media added that the film's second unit would move to Palenque in the state of Chiapas, to film aerial manoeuvres considered too dangerous to shoot in an urban area.
Ans: for filming a sequence involving a fight aboard a Messerschmitt-Bolkow-Blohm Bo 105 helicopter

Extract the answer to the question from the following context. Question: Why did Walpole pack the House of Commons? Context: From 1721 this was the Whig politician Robert Walpole, who held office for twenty-one years. Walpole chaired cabinet meetings, appointed all the other ministers, dispensed the royal patronage and packed the House of Commons with his supporters. Under Walpole, the doctrine of cabinet solidarity developed. Walpole required that no minister other than himself have private dealings with the king, and also that when the cabinet had agreed on a policy, all ministers must defend it in public, or resign. As a later prime minister, Lord Melbourne, said, "It matters not what we say, gentlemen, so long as we all say the same thing."
Ans: cabinet solidarity

Extract the answer to the question from the following context. Question: Why does PCR have difficulty gaining widespread use? Context: Thus, the technological ability to detect any infectious agent rapidly and specifically are currently available. The only remaining blockades to the use of PCR as a standard tool of diagnosis are in its cost and application, neither of which is insurmountable. The diagnosis of a few diseases will not benefit from the development of PCR methods, such as some of the clostridial diseases (tetanus and botulism). These diseases are fundamentally biological poisonings by relatively small numbers of infectious bacteria that produce extremely potent neurotoxins. A significant proliferation of the infectious agent does not occur, this limits the ability of PCR to detect the presence of any bacteria.
Ans: cost and application

Extract the answer to the question from the following context. Question: In a duel-input USB cable, what isn't both cables used for? Context: Some USB devices require more power than is permitted by the specifications for a single port. This is common for external hard and optical disc drives, and generally for devices with motors or lamps. Such devices can use an external power supply, which is allowed by the standard, or use a dual-input USB cable, one input of which is used for power and data transfer, the other solely for power, which makes the device a non-standard USB device. Some USB ports and external hubs can, in practice, supply more power to USB devices than required by the specification but a standard-compliant device may not depend on this.
Ans: data transfer