A lower pair is an ideal joint that constrains contact between a surface in the moving body to a corresponding surface in the fixed body. A lower pair is one in which there occurs a surface or area contact between two members, e.g. nut and screw, universal joint used to connect two propeller shafts. Cases of lower joints:

Answer this question: universal joint is an example of which pair? Let's do a good job answering this.
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Stream of consciousness: The relevant information is: A lower pair is one in which there occurs a surface or area contact between two members, e.g. nut and screw, universal joint used to connect two propeller shafts.... The answer is A lower pair.

Smallville is an American television series developed by writer-producers Alfred Gough and Miles Millar, based on the DC Comics character Superman created by Jerry Siegel and Joe Shuster. The series, initially broadcast by The WB, premiered on October 16, 2001. After Smallville's fifth season, The WB and UPN merged to form The CW, the series' later United States broadcaster. Smallville, which ended its tenth and final season on May 13, 2011, follows Clark Kent (Tom Welling) in the fictional town of Smallville, Kansas, before he becomes known as Superman. The first four seasons focus on Clark and his friends in high school. After season five Smallville ventures into adult settings, eventually focusing on his career at the Daily Planet and introducing other DC comic-book superheroes and villains.

Answer this question based on the passage: who played superman in the tv series smallville? Let's do a good job answering this.
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Stream of consciousness: To answer the above question, the relevant sentence is: Smallville, which ended its tenth and final season on May 13, 2011, follows Clark Kent (Tom Welling) in the fictional town of Smallville, Kansas, before he becomes known as Superman.... The answer is Tom Welling.

Context: In electrocardiography, the PR interval is the period, measured in milliseconds, that extends from the beginning of the P wave (the onset of atrial depolarization) until the beginning of the QRS complex (the onset of ventricular depolarization); it is normally between 120 and 200ms in duration. The PR interval is sometimes termed the PQ interval.

Question: what is the significance of the pq interval? Let's do a good job answering this.
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Stream of consciousness: To answer the question, consider the following: In electrocardiography, the PR interval is the period, measured in milliseconds, that extends from the beginning of the P wave (the onset of atrial depolarization) until the beginning of the QRS complex (the onset of ventricular depolarization); it is normally between 120 and 200ms in duration.... The answer is the period , measured in milliseconds , that extends from the beginning of the P wave ( the onset of atrial depolarization ) until the beginning of the QRS complex ( the onset of ventricular depolarization ).