Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.

Ex Input:
Paragraph- Sent 1: Triumph and Disaster: The 20th century saw a stupendous release of energies that had been pent up for the 250 years of Tokugawa isolation.
Sent 2: By 1930 raw-material production had tripled the figure of 1900, manufactured goods had increased twelve-fold, and heavy industry was galloping towards maturity.
Sent 3: Britain led the World War I Ailies in large orders for munitions, while Japan expanded sales of manufactured goods to Asian and other markets cut off from their usual European suppliers.
Sent 4: Merchant shipping doubled in size and increased its income ten-fold as the European fleets were destroyed.
Sent 5: Setbacks in the 1930s caused by the European postwar slump were only a spur to redouble efforts by diversifying heavy industry into the machine-making, metallurgical, and chemical sectors.
Sent 6: Even the terrible 1923 Tokyo earthquake, which cost over 100,000 lives and billions of dollars, provided another stimulus due to the construction boom that followed.
Sent 7: Riding the crest of this economic upsurge were the zaibatsu conglomerates — a dozen family-run combines, each involved in mining, manufacturing, marketing, shipping, and banking.
Sent 8: These tightly controlled commercial pyramids were the true heirs to the old feudal structures.
Sent 9: Japan's progress toward parliamentary democracy was halted in the 1930s by the growing nationalism being imposed on government by the generals and admirals.
Sent 10: They proclaimed Japan's mission to bring progress to its backward Asian neighbors in language not so very different from that of the Europeans in Africa or the US in Latin America.
Sent 11: After the Russian Revolution of 1917, the Soviet Union was regarded as a major threat to Japan's security, and the army felt it needed Manchuria and whatever other Chinese territory it could control as a buffer against Russian advances.
Sent 12: In 1931 the Japanese occupied Manchuria.
Sent 13: And then in 1937, with the popular support of ultra-right-wing groups, the army overrode parliamentary resistance in Tokyo and went to war against the Chinese Nationalists.
Sent 14: By 1938, they held Nanking, Hankow, and Canton.
Sent 15: Japanese expansionist policies were leading to direct confrontation with the West.
Sent 16: Japan hoped that war in Europe would divert the Soviet Union from interference in East Asia, giving Japan a free hand both in China and, through its alliance with Germany, in French IndoChina after the defeat of France.
Sent 17: The US responded to the Japanese invasion of IndoChina with a trade and fuel embargo, cutting off 90 percent of Japan's supplies.
Sent 18: The result was the attack on the American fleet at Pearl Harbor (7 December 1941) and total war. 
Question: What resulted in the attack on the American fleet at Pearl Harbor?.

Ex Output:
The trade and fuel embargo.


Ex Input:
Paragraph- Sent 1: Hurlburt Field, Florida (CNN) -- An Air Force CV-22 Osprey crashed Wednesday during a routine training mission north of Navarre, Florida, injuring five crew members aboard, a military official said.
Sent 2: The crash occurred about 6:45 p.m.
Sent 3: at Hurlburt Field's Eglin Range, said Amy Nicholson, chief of public affairs at the airfield.
Sent 4: The five injured crew members were taken to an area hospital, Nicholson said.
Sent 5: The extent of their injuries was not immediately known.
Sent 6: The cause of the accident is under investigation, she said.
Sent 7: The Osprey was assigned to the 1st Special Operations Wing, the Air Force said.
Sent 8: The tilt-rotor aircraft can fly like an airplane and land like a helicopter.
Sent 9: The Army began developing the Osprey in 1982, though the program was nearly scrapped in 1989 when then-Secretary of Defense Dick Cheney sought to cancel it because of ballooning costs.
Sent 10: Questions were raised about the safety of the Osprey after two crashes, including one in 1992 at a Marine Corps air base in Virginia that killed the crew.
Sent 11: In late 2000, the Marine Corps grounded the Osprey fleet after two crashes -- one in Arizona that killed four crew members and 15 passengers, and another in North Carolina that killed the crew.
Sent 12: A redesign was ordered on the Osprey, and it resumed flights in 2002.
Sent 13: The Air Force began using Ospreys in 2008 after testing the aircraft in 2006.
Sent 14: They were first deployed by the Marines in Iraq in 2007 after 18 years and $20 billion in development. 
Question: How many crashes was the CV-22 involved in?.

Ex Output:
4.


Ex Input:
Paragraph- Sent 1: You may wonder if there are other examples of static discharge.
Sent 2: The answer is yes.
Sent 3: Lightning is a form of static discharge.
Sent 4: It is much more dramatic than what happens between you and the door knocker, but it is the same principle.
Sent 5: You can see how it occurs in the following diagram and animation.
Sent 6: You have no doubt seen lightning in a rainstorm.
Sent 7: What does lighting have to do with static electricity?
Sent 8: As it turns out, everything!
Sent 9: During a rainstorm, clouds develop regions of different charges.
Sent 10: This happens due to the movement of air molecules, water drops, and ice particles.
Sent 11: The negative charges are concentrated at the base of the clouds.
Sent 12: The positive charges are concentrated at the top.
Sent 13: The negative charges repel electrons on the ground below.
Sent 14: The ground then becomes positively charged.
Sent 15: Over time the differences increase.
Sent 16: Eventually the electrons are discharged.
Sent 17: This is what we see as lightning.
Sent 18: You can watch an awesome slow-motion lightning strike below. 
Question: How is the top of a cloud different from the base of the cloud during a rainstorm?.

Ex Output:

The positive charges are concentrated at the top.


