In 1906, the tungsten filament was introduced. Tungsten metal was initially not available in a form that allowed it to be drawn into fine wires. Filaments made from sintered tungsten powder were quite fragile. By 1910, a process was developed by William D. Coolidge at General Electric for production of a ductile form of tungsten. The process required pressing tungsten powder into bars, then several steps of sintering, swaging, and then wire drawing. It was found that very pure tungsten formed filaments that sagged in use, and that a very small "doping" treatment with potassium, silicon, and aluminium oxides at the level of a few hundred parts per million greatly improved the life and durability of the tungsten filaments.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was introduced in 1900?
Ah, so.. unanswerable

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.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many railroads have tried 4-phase?
Ah, so.. unanswerable

In 2005, the number of public employees per thousand inhabitants in the Portuguese government (70.8) was above the European Union average (62.4 per thousand inhabitants). By EU and USA standards, Portugal's justice system was internationally known as being slow and inefficient, and by 2011 it was the second slowest in Western Europe (after Italy); conversely, Portugal has one of the highest rates of judges and prosecutorsover 30 per 100,000 people. The entire Portuguese public service has been known for its mismanagement, useless redundancies, waste, excess of bureaucracy and a general lack of productivity in certain sectors, particularly in justice.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was the average number of public employees per every thousand inhabitants for the European Union in 2005?
Ah, so..
62.4