Article: AA gunnery was a difficult business. The problem was of successfully aiming a shell to burst close to its target's future position, with various factors affecting the shells' predicted trajectory. This was called deflection gun-laying, 'off-set' angles for range and elevation were set on the gunsight and updated as their target moved. In this method when the sights were on the target, the barrel was pointed at the target's future position. Range and height of the target determined fuse length. The difficulties increased as aircraft performance improved.

Question: What was updated on the gunsight as a target moved?
Ans: 'off-set' angles for range and elevation

Article: In the resulting Battle of Pusan Perimeter (AugustSeptember 1950), the U.S. Army withstood KPA attacks meant to capture the city at the Naktong Bulge, P'ohang-dong, and Taegu. The United States Air Force (USAF) interrupted KPA logistics with 40 daily ground support sorties that destroyed 32 bridges, halting most daytime road and rail traffic. KPA forces were forced to hide in tunnels by day and move only at night. To deny materiel to the KPA, the USAF destroyed logistics depots, petroleum refineries, and harbors, while the U.S. Navy air forces attacked transport hubs. Consequently, the over-extended KPA could not be supplied throughout the south. On 27 August, 67th Fighter Squadron aircraft mistakenly attacked facilities in Chinese territory and the Soviet Union called the UN Security Council's attention to China's complaint about the incident. The US proposed that a commission of India and Sweden determine what the US should pay in compensation but the Soviets vetoed the US proposal.

Question: Along with India, what other nation was to determine the how much the US would have to compensate China?
Ans: Sweden

Article: From 1898, it was commonly accepted that the name was of Celtic origin and meant place belonging to a man called *Londinos; this explanation has since been rejected. Richard Coates put forward an explanation in 1998 that it is derived from the pre-Celtic Old European *(p)lowonida, meaning 'river too wide to ford', and suggested that this was a name given to the part of the River Thames which flows through London; from this, the settlement gained the Celtic form of its name, *Lowonidonjon; this requires quite a serious amendment however. The ultimate difficulty lies in reconciling the Latin form Londinium with the modern Welsh Llundain, which should demand a form *(h)londinion (as opposed to *londinion), from earlier *loundiniom. The possibility cannot be ruled out that the Welsh name was borrowed back in from English at a later date, and thus cannot be used as a basis from which to reconstruct the original name.

Question: What is the modern Welsh form o the word London?
Ans: Llundain

Article: The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an impact. Collectively, these are called vacuum technique. And sometimes, the final pressure is not the only relevant characteristic. Pumping systems differ in oil contamination, vibration, preferential pumping of certain gases, pump-down speeds, intermittent duty cycle, reliability, or tolerance to high leakage rates.

Question: What are two other relevant characteristics of a pumping system along with final pressure?
Ans:
oil contamination, vibration