Q: I know that the answer to the question "Why has 3-phase AC transmission not been relied on more often for trains?" is in "There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation inherent with AC, and on a railway this also reduces interference with signalling and communications and mitigates hypothetical EMF risks. DC also avoids the power factor problems of AC. Of particular interest to railroading is that DC can supply constant power with a single ungrounded wire. Constant power with AC requires three-phase transmission with at least two ungrounded wires. Another important consideration is that mains-frequency 3-phase AC must be carefully planned to avoid unbalanced phase loads. Parts of the system are supplied from different phases on the assumption that the total loads of the 3 phases will even out. At the phase break points between regions supplied from different phases, long insulated supply breaks are required to avoid them being shorted by rolling stock using more than one pantograph at a time. A few railroads have tried 3-phase but its substantial complexity has made single-phase standard practice despite the interruption in power flow that occurs twice every cycle. An experimental 6 kV DC railway was built in the Soviet Union.". Can you tell me what it is?
A: substantial complexity

Q: I know that the answer to the question "Which budget is higher HUMINT or SIGINT?" is in "Details of the overall United States intelligence budget are classified. Under the Central Intelligence Agency Act of 1949, the Director of Central Intelligence is the only federal government employee who can spend "un-vouchered" government money. The government has disclosed a total figure for all non-military intelligence spending since 2007; the fiscal 2013 figure is $52.6 billion. According to the 2013 mass surveillance disclosures, the CIA's fiscal 2013 budget is $14.7 billion, 28% of the total and almost 50% more than the budget of the National Security Agency. CIA's HUMINT budget is $2.3 billion, the SIGINT budget is $1.7 billion, and spending for security and logistics of CIA missions is $2.5 billion. "Covert action programs", including a variety of activities such as the CIA's drone fleet and anti-Iranian nuclear program activities, accounts for $2.6 billion.". Can you tell me what it is?
A: HUMINT

Q: I know that the answer to the question "What addition would raise the number of persons aboard a ship?" is in "The Royal Navy is constructing two new larger STOVL aircraft carriers, the Queen Elizabeth class, to replace the three now retired Invincible-class carriers. The ships are HMS Queen Elizabeth and HMS Prince of Wales. They will be able to operate up to 40 aircraft on peace time operations with a tailored group of up to 50, and will have a displacement of 70,600 tonnes. HMS Queen Elizabeth is projected to commission in 2017 followed by Prince of Wales in about 2020. The ships are due to become operational starting in 2020. Their primary aircraft complement will be made up of F-35B Lightning IIs, and their ship's company will number around 680 with the total complement rising to about 1600 when the air group is embarked. The two ships will be the largest warships ever built for the Royal Navy.". Can you tell me what it is?
A: when the air group is embarked

Q: I know that the answer to the question "In it's simplest form, what greatly accelerated the launch of the products?" is in "On August 1, 2012, Windows 8 (build 9200) was released to manufacturing with the build number 6.2.9200.16384 . Microsoft planned to hold a launch event on October 25, 2012 and release Windows 8 for general availability on the next day. However, only a day after its release to manufacturing, a copy of the final version of Windows 8 Enterprise N (a version for European markets lacking bundled media players to comply with a court ruling) leaked online, followed by leaks of the final versions of Windows 8 Pro and Enterprise a few days later. On August 15, 2012, Windows 8 was made available to download for MSDN and TechNet subscribers. Windows 8 was made available to Software Assurance customers on August 16, 2012. Windows 8 was made available for students with a DreamSpark Premium subscription on August 22, 2012, earlier than advertised.". Can you tell me what it is?
A:
leaks