Input: Read this: Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using power electronics). Thus both systems are faced with the same task: converting and transporting high-voltage AC from the power grid to low-voltage DC in the locomotive. Where should this conversion take place and at what voltage and current (AC or DC) should the power flow to the locomotive? And how does all this relate to energy-efficiency? Both the transmission and conversion of electric energy involve losses: ohmic losses in wires and power electronics, magnetic field losses in transformers and smoothing reactors (inductors). Power conversion for a DC system takes place mainly in a railway substation where large, heavy, and more efficient hardware can be used as compared to an AC system where conversion takes place aboard the locomotive where space is limited and losses are significantly higher. Also, the energy used to blow air to cool transformers, power electronics (including rectifiers), and other conversion hardware must be accounted for.
Question: What is the main action AC and DC systems have to deal with?

Output: converting and transporting

Input: Read this: By the late 1960s, many of the resort's once great hotels were suffering from embarrassing vacancy rates. Most of them were either shut down, converted to cheap apartments, or converted to nursing home facilities by the end of the decade. Prior to and during the advent of legalized gaming, many of these hotels were demolished. The Breakers, the Chelsea, the Brighton, the Shelburne, the Mayflower, the Traymore, and the Marlborough-Blenheim were demolished in the 1970s and 1980s. Of the many pre-casino resorts that bordered the boardwalk, only the Claridge, the Dennis, the Ritz-Carlton, and the Haddon Hall survive to this day as parts of Bally's Atlantic City, a condo complex, and Resorts Atlantic City. The old Ambassador Hotel was purchased by Ramada in 1978 and was gutted to become the Tropicana Casino and Resort Atlantic City, only reusing the steelwork of the original building. Smaller hotels off the boardwalk, such as the Madison also survived.
Question: Prior to and during the advent of legalized gaming, what happened to many of the hotels in Atlantic City?

Output: demolished

Input: Read this: Capital punishment was suspended in the United States from 1972 through 1976 primarily as a result of the Supreme Court's decision in Furman v. Georgia. The last pre-Furman execution was that of Luis Monge on June 2, 1967. In this case, the court found that the death penalty was being imposed in an unconstitutional manner, on the grounds of cruel and unusual punishment in violation of the Eighth Amendment to the United States Constitution. The Supreme Court has never ruled the death penalty to be per se unconstitutional.
Question: In what year was the suspension of the death penalty in South America ended?

Output: unanswerable

Input: Read this: The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.
Question: What has been studied as a mechanism of disease transmission?

Output:
bird migration