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.

Passage: The original services of an inn are now also available at other establishments, such as hotels, lodges, and motels, which focus more on lodging customers than on other services, although they usually provide meals; pubs, which are primarily alcohol-serving establishments; and restaurants and taverns, which serve food and drink. In North America, the lodging aspect of the word "inn" lives on in hotel brand names like Holiday Inn, and in some state laws that refer to lodging operators as innkeepers. Question: In the United States, what are operators of lodgings sometimes called?
innkeepers

Passage: An electromagnetic wave refractor in some aperture antennas is a component which due to its shape and position functions to selectively delay or advance portions of the electromagnetic wavefront passing through it. The refractor alters the spatial characteristics of the wave on one side relative to the other side. It can, for instance, bring the wave to a focus or alter the wave front in other ways, generally in order to maximize the directivity of the antenna system. This is the radio equivalent of an optical lens. Question: What is used to allow one to control the function of wave fronts moving through an antenna?
selectively delay

Passage: West of Fort Washington Avenue, 181st Street is largely residential, bordering Hudson Heights and having a few shops to serve the local residents. East of Fort Washington Avenue, the street becomes increasingly commercial, becoming dominated entirely by retail stores where the street reaches Broadway and continues as such until reaching the Harlem River. It is the area's major shopping district. Question: Which river touches the major shopping district near 181st Street?

Harlem