Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The USAF is the only branch of the U.S. military where NCO status is achieved when an enlisted person reaches the pay grade of E-5. In all other branches, NCO status is generally achieved at the pay grade of E-4 (e.g., a Corporal in the Army and Marine Corps, Petty Officer Third Class in the Navy and Coast Guard). The Air Force mirrored the Army from 1976 to 1991 with an E-4 being either a Senior Airman wearing three stripes without a star or a Sergeant (referred to as "Buck Sergeant"), which was noted by the presence of the central star and considered an NCO. Despite not being an NCO, a Senior Airman who has completed Airman Leadership School can be a supervisor according to the AFI 36-2618.
What rank is NCO status achieved in the US Army?
A: Corporal

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The territory that now constitutes Tajikistan was previously home to several ancient cultures, including the city of Sarazm of the Neolithic and the Bronze Age, and was later home to kingdoms ruled by people of different faiths and cultures, including the Oxus civilization, Andronovo culture, Buddhism, Nestorian Christianity, Zoroastrianism, and Manichaeism. The area has been ruled by numerous empires and dynasties, including the Achaemenid Empire, Sassanian Empire, Hephthalite Empire, Samanid Empire, Mongol Empire, Timurid dynasty, and the Russian Empire. As a result of the breakup of the Soviet Union, Tajikistan became an independent nation in 1991. A civil war was fought almost immediately after independence, lasting from 1992 to 1997. Since the end of the war, newly established political stability and foreign aid have allowed the country's economy to grow.
A civil war was fought immediately before what?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In July 2009, Dell apologized after drawing the ire of the Taiwanese Consumer Protection Commission for twice refusing to honour a flood of orders against unusually low prices offered on its Taiwanese website. In the first instance, Dell offered a 19" LCD panel for $15. In the second instance, Dell offered its Latitude E4300 notebook at NT$18,558 (US$580), 70% lower than usual price of NT$60,900 (US$1900). Concerning the E4300, rather than honour the discount taking a significant loss, the firm withdrew orders and offered a voucher of up to NT$20,000 (US$625) a customer in compensation. The consumer rights authorities in Taiwan fined Dell NT$1 million (US$31250) for customer rights infringements. Many consumers sued the firm for the unfair compensation. A court in southern Taiwan ordered the firm to deliver 18 laptops and 76 flat-panel monitors to 31 consumers for NT$490,000 (US$15,120), less than a third of the normal price. The court said the event could hardly be regarded as mistakes, as the prestigious firm said the company mispriced its products twice in Taiwanese website within 3 weeks.
How much didn't Taiwan fine Dell for its practices?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
When a molten metal is mixed with another substance, there are two mechanisms that can cause an alloy to form, called atom exchange and the interstitial mechanism. The relative size of each element in the mix plays a primary role in determining which mechanism will occur. When the atoms are relatively similar in size, the atom exchange method usually happens, where some of the atoms composing the metallic crystals are substituted with atoms of the other constituent. This is called a substitutional alloy. Examples of substitutional alloys include bronze and brass, in which some of the copper atoms are substituted with either tin or zinc atoms. With the interstitial mechanism, one atom is usually much smaller than the other, so cannot successfully replace an atom in the crystals of the base metal. The smaller atoms become trapped in the spaces between the atoms in the crystal matrix, called the interstices. This is referred to as an interstitial alloy. Steel is an example of an interstitial alloy, because the very small carbon atoms fit into interstices of the iron matrix. Stainless steel is an example of a combination of interstitial and substitutional alloys, because the carbon atoms fit into the interstices, but some of the iron atoms are replaced with nickel and chromium atoms.
Tin or zinc atoms in place of copper atoms create?
A:
substitutional alloys