Problem: An early advantage of AC is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently, the development of very high power semiconductors has caused the classic "universal" AC/DC motor to be largely replaced with the three-phase induction motor fed by a variable frequency drive, a special inverter that varies both frequency and voltage to control motor speed. These drives can run equally well on DC or AC of any frequency, and many modern electric locomotives are designed to handle different supply voltages and frequencies to simplify cross-border operation.
How can different range of voltages be supplied for AC locomotives?
The answer is the following: multiple taps on the transformer

Problem: Continental Portugal's 89,015 km2 (34,369 sq mi) territory is serviced by four international airports located near the principal cities of Lisbon, Porto, Faro and Beja. Lisbon's geographical position makes it a stopover for many foreign airlines at several airports within the country. The primary flag-carrier is TAP Portugal, although many other domestic airlines provide services within and without the country. The government decided to build a new airport outside Lisbon, in Alcochete, to replace Lisbon Portela Airport, though this plan has been stalled due to the austerity. Currently, the most important airports are in Lisbon, Porto, Faro, Funchal (Madeira), and Ponta Delgada (Azores), managed by the national airport authority group ANA Aeroportos de Portugal.
Near what cities are the Portuguese airports located?
The answer is the following: Lisbon, Porto, Faro and Beja

Problem: In Europe the Wayback Machine could be interpreted as violating copyright laws. Only the content creator can decide where their content is published or duplicated, so the Archive would have to delete pages from its system upon request of the creator. The exclusion policies for the Wayback Machine may be found in the FAQ section of the site. The Wayback Machine also retroactively respects robots.txt files, i.e., pages that currently are blocked to robots on the live web temporarily will be made unavailable from the archives as well.
What kinds of laws could the Wayback Machine be viewed as breaking in Europe?
The answer is the following: copyright laws

Problem: Most of the UK's Caribbean territories achieved independence after the departure in 1961 and 1962 of Jamaica and Trinidad from the West Indies Federation, established in 1958 in an attempt to unite the British Caribbean colonies under one government, but which collapsed following the loss of its two largest members. Barbados achieved independence in 1966 and the remainder of the eastern Caribbean islands in the 1970s and 1980s, but Anguilla and the Turks and Caicos Islands opted to revert to British rule after they had already started on the path to independence. The British Virgin Islands, Cayman Islands and Montserrat opted to retain ties with Britain, while Guyana achieved independence in 1966. Britain's last colony on the American mainland, British Honduras, became a self-governing colony in 1964 and was renamed Belize in 1973, achieving full independence in 1981. A dispute with Guatemala over claims to Belize was left unresolved.
What was Britain's last American mainland colony?
The answer is the following:
British Honduras