Problem: Sichuan:

Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.

What region was liberated by the Tibetan Empire?
---
A: unanswerable

Problem: Menzies ran strongly against Labor's plans to nationalise the Australian banking system and, following victory in the 1949 election, secured a double dissolution election for April 1951, after the Labor-controlled Senate refused to pass his banking legislation. The Liberal-Country Coalition was returned with control of the Senate. The Government was returned again in the 1954 election; the formation of the anti-Communist Democratic Labor Party (DLP) and the consequent split in the Australian Labor Party early in 1955 helped the Liberals to another victory in December 1955. John McEwen replaced Arthur Fadden as leader of the Country Party in March 1958 and the Menzies-McEwen Coalition was returned again at elections in November 1958 their third victory against Labor's H. V. Evatt. The Coalition was narrowly returned against Labor's Arthur Calwell in the December 1961 election, in the midst of a credit squeeze. Menzies stood for office for the last time in the November 1963 election, again defeating Calwell, with the Coalition winning back its losses in the House of Representatives. Menzies went on to resign from parliament on 26 January 1966.
When did Evatt resign from Parliament?
---
Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Islamic Prophet Muhammad carried out a siege against the Banu Qaynuqa tribe known as the Invasion of Banu Qaynuqa in February 624 Muhammad ordered his followers to attack the Banu Qaynuqa Jews for allegedly breaking the treaty known as the Constitution of Medina by pinning the clothes of a Muslim woman, which led to her being stripped naked As a result, a Muslim killed a Jew in retaliation, and the Jews in turn killed the Muslim man. This escalated to a chain of revenge killings, and enmity grew between Muslims and the Banu Qaynuqa, leading to the siege of their fortress.:122 The tribe eventually surrendered to Muhammad, who initially wanted to kill the members of Banu Qaynuqa but ultimately yielded to Abdullah ibn Ubayy's insistence and agreed to expel the Qaynuqa.
Muhammad ordered his followers to attack the Banu Qaynuqa Jews for allegedly breaking what treaty?
A: the Constitution of Medina

Context and question: USB mice and keyboards can usually be used with older computers that have PS/2 connectors with the aid of a small USB-to-PS/2 adapter. For mice and keyboards with dual-protocol support, an adaptor that contains no logic circuitry may be used: the hardware in the USB keyboard or mouse is designed to detect whether it is connected to a USB or PS/2 port, and communicate using the appropriate protocol. Converters also exist that connect PS/2 keyboards and mice (usually one of each) to a USB port. These devices present two HID endpoints to the system and use a microcontroller to perform bidirectional data translation between the two standards.
What do older computers have to have in order for USB mice and keyboards to be used?
Answer: PS/2 connectors with the aid of a small USB-to-PS/2 adapter

Question: The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. This pericardial sac is filled with a serous fluid for lubrication. The heart itself is divided into a right and left half, each with an atrium and ventricle. The atrium and ventricles of each side are separated by atrioventricular valves which prevent back flow from one chamber to the next during contraction. Being myogenic, the heart's pace is maintained by pacemaker cells found in the sinoatrial node, located on the right atrium. The sinoatrial node uses calcium to cause a depolarizing signal transduction pathway from the atrium through right and left atrioventricular bundle which communicates contraction to the ventricles. The avian heart also consists of muscular arches that are made up of thick bundles of muscular layers. Much like a mammalian heart, the avian heart is composed of endocardial, myocardial and epicardial layers. The atrium walls tend to be thinner than the ventricle walls, due to the intense ventricular contraction used to pump oxygenated blood throughout the body. Avian hearts are generally larger than mammalian hearts when compared to body mass. This adaptation allows more blood to be pumped to meet the high metabolic need associated with flight.
Is there an answer to this question: What lubricates the pericardial sac?

Answer: serous fluid

Standing out in Clarke's (and Newton's) response to Leibniz's arguments is the bucket argument: Water in a bucket, hung from a rope and set to spin, will start with a flat surface. As the water begins to spin in the bucket, the surface of the water will become concave. If the bucket is stopped, the water will continue to spin, and while the spin continues, the surface will remain concave. The concave surface is apparently not the result of the interaction of the bucket and the water, since the surface is flat when the bucket first starts to spin, it becomes concave as the water starts to spin, and it remains concave as the bucket stops.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is the surface of the water apparently not caused by?
Ah, so..
the interaction of the bucket and the water