Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Bronx is almost entirely situated on the North American mainland. The Hudson River separates the Bronx on the west from Alpine, Tenafly and Englewood Cliffs in Bergen County, New Jersey; the Harlem River separates it from the island of Manhattan to the southwest; the East River separates it from Queens to the southeast; and to the east, Long Island Sound separates it from Nassau County in western Long Island. Directly north of the Bronx are (from west to east) the adjoining Westchester County communities of Yonkers, Mount Vernon, Pelham Manor and New Rochelle. (There is also a short southern land boundary with Marble Hill in the Borough of Manhattan, over the filled-in former course of the Spuyten Duyvil Creek. Marble Hill's postal ZIP code, telephonic Area Code and fire service, however, are shared with the Bronx and not Manhattan.)
What's on the other side of the East River from the Bronx?
A: Queens

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Under the Qing dynasty (16441911), the Nanjing area was known as Jiangning () and served as the seat of government for the Viceroy of Liangjiang. It had been visited by the Kangxi and Qianlong emperors a number of times on their tours of the southern provinces. Nanjing was invaded by British troops during the close of the First Opium War, which was ended by the Treaty of Nanjing in 1842. As the capital of the brief-lived rebel Taiping Heavenly Kingdom (founded by the Taiping rebels in the mid-19th century, Nanjing was known as Tianjing (, "Heavenly Capital" or "Capital of Heaven").
When was the Qing dynasty in power?
A: 16441911

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
New Haven is a notable center for higher education. Yale University, at the heart of downtown, is one of the city's best known features and its largest employer. New Haven is also home to Southern Connecticut State University, part of the Connecticut State University System, and Albertus Magnus College, a private institution. Gateway Community College has a campus in downtown New Haven, formerly located in the Long Wharf district; Gateway consolidated into one campus downtown into a new state-of-the-art campus (on the site of the old Macy's building) and was open for the Fall 2012 semester.
Before relocating to downtown area, New Haven has a community college that used to be located where?
A: Long Wharf district

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Reflections generally affect polarization. For radio waves, one important reflector is the ionosphere which can change the wave's polarization. Thus for signals received following reflection by the ionosphere (a skywave), a consistent polarization cannot be expected. For line-of-sight communications or ground wave propagation, horizontally or vertically polarized transmissions generally remain in about the same polarization state at the receiving location. Matching the receiving antenna's polarization to that of the transmitter can make a very substantial difference in received signal strength.
What reflector can change the waves polarization?
A:
ionosphere