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 Q]: Passage: Israel retaliated against Egyptian shelling with commando raids, artillery shelling and air strikes. This resulted in an exodus of civilians from Egyptian cities along the Suez Canal's western bank. Nasser ceased all military activities and began a program to build a network of internal defenses, while receiving the financial backing of various Arab states. The war resumed in March 1969. In November, Nasser brokered an agreement between the PLO and the Lebanese military that granted Palestinian guerrillas the right to use Lebanese territory to attack Israel. Question: Who would get to attack Israel from Lebanon?
[EX A]: Palestinian guerrillas

[EX Q]: Passage: The word phonology comes from the Greek , phone, "voice, sound," and the suffix -logy (which is from Greek , logos, "word, speech, subject of discussion"). Definitions of the term vary. Nikolai Trubetzkoy in Grundzuge der Phonologie (1939) defines phonology as "the study of sound pertaining to the system of language," as opposed to phonetics, which is "the study of sound pertaining to the act of speech" (the distinction between language and speech being basically Saussure's distinction between langue and parole). More recently, Lass (1998) writes that phonology refers broadly to the subdiscipline of linguistics concerned with the sounds of language, while in more narrow terms, "phonology proper is concerned with the function, behavior and organization of sounds as linguistic items." According to Clark et al. (2007), it means the systematic use of sound to encode meaning in any spoken human language, or the field of linguistics studying this use. Question: Who in 1939 defined phonology?
[EX A]: Nikolai Trubetzkoy

[EX Q]: Passage: Typical of Slavic languages, Czech marks its verbs for one of two grammatical aspects: perfective and imperfective. Most verbs are part of inflected aspect pairsfor example, koupit (perfective) and kupovat (imperfective). Although the verbs' meaning is similar, in perfective verbs the action is completed and in imperfective verbs it is ongoing. This is distinct from past and present tense, and any Czech verb of either aspect can be conjugated into any of its three tenses. Aspect describes the state of the action at the time specified by the tense. Question: What two grammatical aspects can verbs in Czech have?
[EX A]:
perfective and imperfective