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: Uranium is a naturally occurring element that can be found in low levels within all rock, soil, and water. Uranium is the 51st element in order of abundance in the Earth's crust. Uranium is also the highest-numbered element to be found naturally in significant quantities on Earth and is almost always found combined with other elements. Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernovae. The decay of uranium, thorium, and potassium-40 in the Earth's mantle is thought to be the main source of heat that keeps the outer core liquid and drives mantle convection, which in turn drives plate tectonics. Question: Where does uranium rank among elements in terms of its abundance in the Earth's crust?

SOLUTION: 51st

PROBLEM: Passage: Photorespiration can occur when the oxygen concentration is too high. Rubisco cannot distinguish between oxygen and carbon dioxide very well, so it can accidentally add O2 instead of CO2 to RuBP. This process reduces the efficiency of photosynthesis—it consumes ATP and oxygen, releases CO2, and produces no sugar. It can waste up to half the carbon fixed by the Calvin cycle. Several mechanisms have evolved in different lineages that raise the carbon dioxide concentration relative to oxygen within the chloroplast, increasing the efficiency of photosynthesis. These mechanisms are called carbon dioxide concentrating mechanisms, or CCMs. These include Crassulacean acid metabolism, C4 carbon fixation, and pyrenoids. Chloroplasts in C4 plants are notable as they exhibit a distinct chloroplast dimorphism. Question: When does photorespiration happen?

SOLUTION: when the oxygen concentration is too high

PROBLEM: Passage: There are few accredited diplomats in Bermuda. The United States maintains the largest diplomatic mission in Bermuda, comprising both the United States Consulate and the US Customs and Border Protection Services at the L.F. Wade International Airport. The current US Consul General is Robert Settje, who took office in August 2012. The United States is Bermuda's largest trading partner (providing over 71% of total imports, 85% of tourist visitors, and an estimated $163 billion of US capital in the Bermuda insurance/re-insurance industry), and an estimated 5% of Bermuda residents are US citizens, representing 14% of all foreign-born persons. The American diplomatic presence is an important element in the Bermuda political landscape. Question: What percentage of Bermuda's residents are US citizens?

SOLUTION:
5%