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.

Example Input: Passage: Cultural and career issues in the U.S. Air Force have been cited as one of the reasons for the shortfall in needed UAV operators. In spite of an urgent need for UAVs or drones to provide round the clock coverage for American troops during the Iraq War, the USAF did not establish a new career field for piloting them until the last year of that war and in 2014 changed its RPA training syllabus again, in the face of large aircraft losses in training, and in response to a GAO report critical of handling of drone programs. Paul Scharre has reported that the cultural divide between the USAF and US Army has kept both services from adopting each other's drone handing innovations. Question: What is the reason for the shortage of UAV operators in the US Air Force?
Example Output: Cultural and career issues

Example Input: Passage: On November 13, 1988, approximately 10,000 people attended an officially sanctioned meeting organized by the cultural heritage organization Spadschyna, the Kyiv University student club Hromada, and the environmental groups Zelenyi Svit ("Green World") and Noosfera, to focus on ecological issues. From November 1418, 15 Ukrainian activists were among the 100 human-, national- and religious-rights advocates invited to discuss human rights with Soviet officials and a visiting delegation of the U.S. Commission on Security and Cooperation in Europe (also known as the Helsinki Commission). On December 10, hundreds gathered in Kiev to observe International Human Rights Day at a rally organized by the Democratic Union. The unauthorized gathering resulted in the detention of local activists. Question: What did people gather to observe on December 10th?
Example Output: International Human Rights Day

Example Input: Passage: Proteins are structural materials in much of the animal body (e.g. muscles, skin, and hair). They also form the enzymes that control chemical reactions throughout the body. Each protein molecule is composed of amino acids, which are characterized by inclusion of nitrogen and sometimes sulphur (these components are responsible for the distinctive smell of burning protein, such as the keratin in hair). The body requires amino acids to produce new proteins (protein retention) and to replace damaged proteins (maintenance). As there is no protein or amino acid storage provision, amino acids must be present in the diet. Excess amino acids are discarded, typically in the urine. For all animals, some amino acids are essential (an animal cannot produce them internally) and some are non-essential (the animal can produce them from other nitrogen-containing compounds). About twenty amino acids are found in the human body, and about ten of these are essential and, therefore, must be included in the diet. A diet that contains adequate amounts of amino acids (especially those that are essential) is particularly important in some situations: during early development and maturation, pregnancy, lactation, or injury (a burn, for instance). A complete protein source contains all the essential amino acids; an incomplete protein source lacks one or more of the essential amino acids. Question: What is the primary component of every protein?
Example Output:
amino acids