Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Zinc metal is produced using extractive metallurgy. After grinding the ore, froth flotation, which selectively separates minerals from gangue by taking advantage of differences in their hydrophobicity, is used to get an ore concentrate. This concentrate consists of about 50% zinc with the rest being sulfur (32%), iron (13%), and SiO
2 (5%). The composition of this is normally zinc sulfide (80% to 85%), iron sulfide (7.0% to 12%), lead sulfide (3.0% to 5.0%) silica (2.5% to 3.5%), and cadmium sulfide (0.35% to 0.41%).
What percentage of the s'more concentrate is zinc?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Before the attack on Pearl Harbor, the 800,000-member America First Committee vehemently opposed any American intervention in the European conflict, even as America sold military aid to Britain and the Soviet Union through the Lend-Lease program. Opposition to war in the U.S. vanished after the attack. On 8 December, the United States, the United Kingdom, Canada, and the Netherlands declared war on Japan, followed by China and Australia the next day. Four days after Pearl Harbor, Nazi Germany and Fascist Italy declared war on the United States, drawing the country into a two-theater war. This is widely agreed to be a grand strategic blunder, as it abrogated the benefit Germany gained by Japan's distraction of the U.S. (predicted months before in a memo by Commander Arthur McCollum)[nb 12] and the reduction in aid to Britain, which both Congress and Hitler had managed to avoid during over a year of mutual provocation, which would otherwise have resulted.
On what day did the U.S. and its allies declar war on Japan?
A: 8 December

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In 1987, occupations and units with the primary role of preparing for direct involvement in combat on the ground or at sea were still closed to women: infantry, armoured corps, field artillery, air-defence artillery, signals, field engineers, and naval operations. On 5 February 1987, the Minister of National Defence created an office to study the impact of employing men and women in combat units. These trials were called Combat-Related Employment of Women.
Name some of the teaching opportunities in the CAF off limits to women in the 1980s.
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Chopin arrived in Paris in late September 1831; he would never return to Poland, thus becoming one of many expatriates of the Polish Great Emigration. In France he used the French versions of his given names, and after receiving French citizenship in 1835, he travelled on a French passport. However, Chopin remained close to his fellow Poles in exile as friends and confidants and he never felt fully comfortable speaking French. Chopin's biographer Adam Zamoyski writes that he never considered himself to be French, despite his father's French origins, and always saw himself as a Pole.
What country's passport did he have from 1835?
A:
France