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.

Ex Input:
Passage: The most common cause is an infection of the intestines due to either a virus, bacteria, or parasite; a condition known as gastroenteritis. These infections are often acquired from food or water that has been contaminated by stool, or directly from another person who is infected. It may be divided into three types: short duration watery diarrhea, short duration bloody diarrhea, and if it lasts for more than two weeks, persistent diarrhea. The short duration watery diarrhea may be due to an infection by cholera, although this is rare in the developed world. If blood is present it is also known as dysentery. A number of non-infectious causes may also result in diarrhea, including hyperthyroidism, lactose intolerance, inflammatory bowel disease, a number of medications, and irritable bowel syndrome. In most cases, stool cultures are not required to confirm the exact cause. Question: What can cause an infection in the intestines?

Ex Output:
a virus, bacteria, or parasite


Ex Input:
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?

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


Ex Input:
Passage: During the reign of Khārabēḷa, the Chedi dynasty of Kaḷinga ascended to eminence and restored the lost power and glory of Kaḷinga, which had been subdued since the devastating war with Ashoka. Kaḷingan military might was reinstated by Khārabēḷa: under Khārabēḷa's generalship, the Kaḷinga state had a formidable maritime reach with trade routes linking it to the then-Simhala (Sri Lanka), Burma (Myanmar), Siam (Thailand), Vietnam, Kamboja (Cambodia), Malaysia, Borneo, Bali, Samudra (Sumatra) and Jabadwipa (Java). Khārabēḷa led many successful campaigns against the states of Magadha, Anga, Satavahanas till the southern most regions of Pandyan Empire (modern Tamil Nadu). Question: What power had previously defeated the Kalingans? 

Ex Output:

Ashoka