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.

Ex Input:
Passage: Israel, and The US Air Force, in conjunction with the members of NATO, has developed significant tactics for air defence suppression. Dedicated weapons such as anti-radiation missiles and advanced electronics intelligence and electronic countermeasures platforms seek to suppress or negate the effectiveness of an opposing air-defence system. It is an arms race; as better jamming, countermeasures and anti-radiation weapons are developed, so are better SAM systems with ECCM capabilities and the ability to shoot down anti-radiation missiles and other munitions aimed at them or the targets they are defending. Question: As better weapons are created, what systems continue to improve as well to counter them?

Ex Output:
SAM systems with ECCM capabilities

Ex Input:
Passage: In 2004, a large share of natural gas reserves in Iran were untapped. The addition of new hydroelectric stations and the streamlining of conventional coal and oil-fired stations increased installed capacity to 33,000 megawatts. Of that amount, about 75% was based on natural gas, 18% on oil, and 7% on hydroelectric power. In 2004, Iran opened its first wind-powered and geothermal plants, and the first solar thermal plant is to come online in 2009. Iran is the third country in the world to have developed GTL technology. Question: How much of Iran's 33k megawatt installed capacity was based on oil?

Ex Output:
18%

Ex Input:
Passage: The total adult literacy rate is 99 percent. Portuguese primary school enrollments are close to 100 percent. According to the OECD's Programme for International Student Assessment (PISA) 2009, the average Portuguese 15-year-old student, when rated in terms of reading literacy, mathematics and science knowledge, is placed at the same level as those students from the United States, Sweden, Germany, Ireland, France, Denmark, United Kingdom, Hungary and Taipei, with 489 points (493 is the average). Over 35% of college-age citizens (20 years old) attend one of the country's higher education institutions (compared with 50% in the United States and 35% in the OECD countries). In addition to being a destination for international students, Portugal is also among the top places of origin for international students. All higher education students, both domestic and international, totaled 380,937 in 2005. Question: What percentage of college-age citizens attend a higher education institution in the United States?

Ex Output:
50%