This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
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Question: Immigration to Israel during the late 1940s and early 1950s was aided by the Israeli Immigration Department and the non-government sponsored Mossad LeAliyah Bet ("Institution for Illegal Immigration"). Both groups facilitated regular immigration logistics like arranging transportation, but the latter also engaged in clandestine operations in countries, particularly in the Middle East and Eastern Europe, where the lives of Jews were believed to be in danger and exit from those places was difficult. Mossad LeAliyah Bet continued to take part in immigration efforts until its disbanding in 1953. An influx of Holocaust survivors and Jews from Arab and Muslim lands immigrated to Israel during the first 3 years and the number of Jews increased from 700,000 to 1,400,000, many of whom faced persecution in their original countries. The immigration was in accordance with the One Million Plan.

Answer: Who aided the immigration to Israel?


Question: The Prussian Army, under the terms of the armistice, held a brief victory parade in Paris on 17 February; the city was silent and draped with black and the Germans quickly withdrew. Bismarck honoured the armistice, by allowing train loads of food into Paris and withdrawing Prussian forces to the east of the city, prior to a full withdrawal once France agreed to pay a five billion franc war indemnity. At the same time, Prussian forces were concentrated in the provinces of Alsace and Lorraine. An exodus occurred from Paris as some 200,000 people, predominantly middle-class, went to the countryside.

Answer: What did the Prussian Army hold in Paris on 17 February?


Question: The Houston area is a leading center for building oilfield equipment. Much of its success as a petrochemical complex is due to its busy ship channel, the Port of Houston. In the United States, the port ranks first in international commerce and tenth among the largest ports in the world. Unlike most places, high oil and gasoline prices are beneficial for Houston's economy, as many of its residents are employed in the energy industry. Houston is the beginning or end point of numerous oil, gas, and products pipelines:

Answer:
Of what is Houston a center?