TASK DEFINITION: This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
PROBLEM: Passage: Another potential weapon system for anti-aircraft use is the laser. Although air planners have imagined lasers in combat since the late 1960s, only the most modern laser systems are currently reaching what could be considered "experimental usefulness". In particular the Tactical High Energy Laser can be used in the anti-aircraft and anti-missile role. If current developments continue, some[who?] believe it is reasonable to suggest that lasers will play a major role in air defence starting in the next ten years. Question: When do some people believe that lasers can play a more prominent role in air defence?

SOLUTION: in the next ten years

PROBLEM: Passage: There were 46,917 households, out of which 7,835 (16.7%) had children under the age of 18 living in them, 13,092 (27.9%) were opposite-sex married couples living together, 3,510 (7.5%) had a female householder with no husband present, 1,327 (2.8%) had a male householder with no wife present. There were 2,867 (6.1%) unmarried opposite-sex partnerships, and 416 (0.9%) same-sex married couples or partnerships. 22,716 households (48.4%) were made up of individuals and 5,551 (11.8%) had someone living alone who was 65 years of age or older. The average household size was 1.87. There were 17,929 families (38.2% of all households); the average family size was 2.79. Question: What percent of household have children under 18?

SOLUTION: 16.7%

PROBLEM: Passage: After a new wave of UN sanctions, on 11 March 2013, North Korea claimed that it had invalidated the 1953 armistice. On 13 March 2013, North Korea confirmed it ended the 1953 Armistice and declared North Korea "is not restrained by the North-South declaration on non-aggression". On 30 March 2013, North Korea stated that it had entered a "state of war" with South Korea and declared that "The long-standing situation of the Korean peninsula being neither at peace nor at war is finally over". Speaking on 4 April 2013, the U.S. Secretary of Defense, Chuck Hagel, informed the press that Pyongyang had "formally informed" the Pentagon that it had "ratified" the potential usage of a nuclear weapon against South Korea, Japan and the United States of America, including Guam and Hawaii. Hagel also stated that the United States would deploy the Terminal High Altitude Area Defense anti-ballistic missile system to Guam, because of a credible and realistic nuclear threat from North Korea. Question: How does the United States view North Korea's threats? 

SOLUTION:
credible and realistic nuclear threat