Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
By the end of the decade a distinct genre of hard rock was emerging with bands like Led Zeppelin, who mixed the music of early rock bands with a more hard-edged form of blues rock and acid rock on their first two albums Led Zeppelin (1969) and Led Zeppelin II (1969), and Deep Purple, who began as a progressive rock group but achieved their commercial breakthrough with their fourth and distinctively heavier album, In Rock (1970). Also significant was Black Sabbath's Paranoid (1970), which combined guitar riffs with dissonance and more explicit references to the occult and elements of Gothic horror. All three of these bands have been seen as pivotal in the development of heavy metal, but where metal further accentuated the intensity of the music, with bands like Judas Priest following Sabbath's lead into territory that was often "darker and more menacing", hard rock tended to continue to remain the more exuberant, good-time music.
What was the title of Deep Purple's hard rock 1970 album?
A: In Rock

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
On February 8, 1847, Doniphan continued his march with 924 men mostly from Missouri; he accompanied a train of 315 wagons of a large commercial caravan heading to the state capital. Meanwhile, the Mexican forces in the state had time to prepare a defense against the Americans. About 20 miles (32 km) north of the capital where two mountain ranges join from east to west is the only pass into the capital; known as Sacramento Pass, this point is now part of present-day Chihuahua City. The Battle of Sacramento was the most important battle fought in the state of Chihuahua because it was the sole defense for the state capital. The battle ended quickly because of some devastating defensive errors from the Mexican forces and the ingenious strategic moves by the American forces. After their loss at the Battle of Sacramento, the remaining Mexican soldiers retreated south, leaving the city to American occupation. Almost 300 Mexicans were killed in the battle, as well as almost 300 wounded. The Americans also confiscated large amounts of Mexican supplies and took 400 Mexican soldiers prisoners of war. American forces maintained an occupation of the state capital for the rest of the Mexican–American War.
Which was the most important battle fought in Chihuahua?
A: The Battle of Sacramento

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
During the last century, decreases in biodiversity have been increasingly observed. In 2007, German Federal Environment Minister Sigmar Gabriel cited estimates that up to 30% of all species will be extinct by 2050. Of these, about one eighth of known plant species are threatened with extinction. Estimates reach as high as 140,000 species per year (based on Species-area theory). This figure indicates unsustainable ecological practices, because few species emerge each year.[citation needed] Almost all scientists acknowledge that the rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates. As of 2012, some studies suggest that 25% of all mammal species could be extinct in 20 years.
2012 studies estimated what percentage of mammals could be extinct in 20 years?
A: 25%

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Although the city lost the status of state capital to Columbia in 1786, Charleston became even more prosperous in the plantation-dominated economy of the post-Revolutionary years. The invention of the cotton gin in 1793 revolutionized the processing of this crop, making short-staple cotton profitable. It was more easily grown in the upland areas, and cotton quickly became South Carolina's major export commodity. The Piedmont region was developed into cotton plantations, to which the sea islands and Lowcountry were already devoted. Slaves were also the primary labor force within the city, working as domestics, artisans, market workers, and laborers.
Charleston was the state capital of North Carolina until what year?
A:
unanswerable