instruction:
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
question:
Passage: Within Galicia are the Autopista AP-9 from Ferrol to Vigo and the Autopista AP-53 (also known as AG-53, because it was initially built by the Xunta de Galicia) from Santiago to Ourense. Additional roads under construction include Autovía A-54 from Santiago de Compostela to Lugo, and Autovía A-56 from Lugo to Ourense. The Xunta de Galicia has built roads connecting comarcal capitals, such as the aforementioned AG-53, Autovía AG-55 connecting A Coruña to Carballo or AG-41 connecting Pontevedra to Sanxenxo. Question: The Autopista AP-53 was originally built by whom?
answer:
Xunta de Galicia


question:
Passage: At present, the branches Waal and Nederrijn-Lek discharge to the North Sea, through the former Meuse estuary, near Rotterdam. The river IJssel branch flows to the north and enters the IJsselmeer, formerly the Zuider Zee brackish lagoon; however, since 1932, a freshwater lake. The discharge of the Rhine is divided among three branches: the River Waal (6/9 of total discharge), the River Nederrijn – Lek (2/9 of total discharge) and the River IJssel (1/9 of total discharge). This discharge distribution has been maintained since 1709, by river engineering works, including the digging of the Pannerdens canal and since the 20th century, with the help of weirs in the Nederrijn river. Question: Where does the Ijssel branch flow?
answer:
IJsselmeer


question:
Passage: 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 nowdays electrification systems can use?
answer:

DC motors which directly use the DC or they may be 3-phase AC motors