instruction:
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.
question:
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 photosynthesisit 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?
answer:
when the oxygen concentration is too high

question:
Passage: The revived Georgian style that emerged in Britain at the beginning of the 20th century is usually referred to as Neo-Georgian; the work of Edwin Lutyens includes many examples. Versions of the Neo-Georgian style were commonly used in Britain for certain types of urban architecture until the late 1950s, Bradshaw Gass & Hope's Police Headquarters in Salford of 1958 being a good example. In both the United States and Britain, the Georgian style is still employed by architects like Quinlan Terry Julian Bicknell and Fairfax and Sammons for private residences. Question: Which architects in the US and Britain still employ the Georgian style for private residences?
answer:
Quinlan Terry Julian Bicknell and Fairfax and Sammons

question:
Passage: The 2008 Research Assessment Exercise returned 26% of the 1225 staff submitted as being world-leading (4*) and a further 47% as being internationally excellent (3*). The 2008 Research Assessment Exercise also showed five subjects Pure Mathematics, Epidemiology and Public Health, Chemical Engineering, Civil Engineering, and Mechanical, Aeronautical and Manufacturing Engineering were assessed to be the best[clarification needed] in terms of the proportion of internationally recognised research quality. Question: What percentage of Imperial's staff was classified as world leading in 2008?
answer:
26%