Here is a question about this article: Mu'awiyah introduced postal service, Abd al-Malik extended it throughout his empire, and Walid made full use of it. The Umayyad Caliph Abd al-Malik developed a regular postal service. Umar bin Abdul-Aziz developed it further by building caravanserais at stages along the Khurasan highway. Relays of horses were used for the conveyance of dispatches between the caliph and his agents and officials posted in the provinces. The main highways were divided into stages of 12 miles (19 km) each and each stage had horses, donkeys or camels ready to carry the post. Primarily the service met the needs of Government officials, but travellers and their important dispatches were also benefitted by the system. The postal carriages were also used for the swift transport of troops. They were able to carry fifty to a hundred men at a time. Under Governor Yusuf bin Umar, the postal department of Iraq cost 4,000,000 dirhams a year.
What is the answer to this question: Along with horses and camels, what animals were used by the postal service?
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So... donkeys


Here is a question about this article: The first example is taken from the opening lines of the folk-epic Beowulf, a poem of some 3,000 lines and the single greatest work of Old English. This passage describes how Hrothgar's legendary ancestor Scyld was found as a baby, washed ashore, and adopted by a noble family. The translation is literal and represents the original poetic word order. As such, it is not typical of Old English prose. The modern cognates of original words have been used whenever practical to give a close approximation of the feel of the original poem.
What is the answer to this question: About how many lines was Beowulf?
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So... 3,000


Here is a question about this article: Some people argue that elevators began as simple rope or chain hoists (see Traction elevators below). An elevator is essentially a platform that is either pulled or pushed up by a mechanical means. A modern-day elevator consists of a cab (also called a "cage", "carriage" or "car") mounted on a platform within an enclosed space called a shaft or sometimes a "hoistway". In the past, elevator drive mechanisms were powered by steam and water hydraulic pistons or by hand. In a "traction" elevator, cars are pulled up by means of rolling steel ropes over a deeply grooved pulley, commonly called a sheave in the industry. The weight of the car is balanced by a counterweight. Sometimes two elevators are built so that their cars always move synchronously in opposite directions, and are each other's counterweight.
What is the answer to this question: How do elevators built in pairs work?
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So...
their cars always move synchronously in opposite directions,