Input: Read this: The quality of a vacuum is indicated by the amount of matter remaining in the system, so that a high quality vacuum is one with very little matter left in it. Vacuum is primarily measured by its absolute pressure, but a complete characterization requires further parameters, such as temperature and chemical composition. One of the most important parameters is the mean free path (MFP) of residual gases, which indicates the average distance that molecules will travel between collisions with each other. As the gas density decreases, the MFP increases, and when the MFP is longer than the chamber, pump, spacecraft, or other objects present, the continuum assumptions of fluid mechanics do not apply. This vacuum state is called high vacuum, and the study of fluid flows in this regime is called particle gas dynamics. The MFP of air at atmospheric pressure is very short, 70 nm, but at 100 mPa (~6997100000000000000♠1×10−3 Torr) the MFP of room temperature air is roughly 100 mm, which is on the order of everyday objects such as vacuum tubes. The Crookes radiometer turns when the MFP is larger than the size of the vanes.
Question: How is vacuum generally measured?

Output: its absolute pressure


Input: Read this: In addition to his many other roles, the emperor acted as the highest priest in the land who made sacrifices to Heaven, the main deities known as the Five Powers, and the spirits (shen 神) of mountains and rivers. It was believed that the three realms of Heaven, Earth, and Mankind were linked by natural cycles of yin and yang and the five phases. If the emperor did not behave according to proper ritual, ethics, and morals, he could disrupt the fine balance of these cosmological cycles and cause calamities such as earthquakes, floods, droughts, epidemics, and swarms of locusts.
Question: How many realms were commonly thought of as being linked by a natural cycle?

Output: three realms


Input: Read this: Russell moved the Watch Tower Society's headquarters to Brooklyn, New York, in 1909, combining printing and corporate offices with a house of worship; volunteers were housed in a nearby residence he named Bethel. He identified the religious movement as "Bible Students," and more formally as the International Bible Students Association. By 1910, about 50,000 people worldwide were associated with the movement and congregations re-elected him annually as their "pastor." Russell died October 31, 1916, at the age of 64 while returning from a ministerial speaking tour.
Question: When did Russell die?

Output: October 31, 1916


Input: Read this: The Hudson River flows through the Hudson Valley into New York Bay. Between New York City and Troy, New York, the river is an estuary. The Hudson River separates the city from the U.S. state of New Jersey. The East River—a tidal strait—flows from Long Island Sound and separates the Bronx and Manhattan from Long Island. The Harlem River, another tidal strait between the East and Hudson Rivers, separates most of Manhattan from the Bronx. The Bronx River, which flows through the Bronx and Westchester County, is the only entirely fresh water river in the city.
Question: Into what body of water does the Hudson River terminate?

Output:
New York Bay