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.

Input: Consider 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?

Output: Cultural and career issues

Input: Consider Input: Passage: Many more artillery pieces had arrived and been dug into batteries. In June, a third bombardment was followed after two days by a successful attack on the Mamelon, but a follow-up assault on the Malakoff failed with heavy losses. During this time the garrison commander, Admiral Nakhimov fell on 30 June 1855.:378 Raglan having also died on 28 June.:460 In August, the Russians again made an attack towards the base at Balaclava, defended by the French, newly arrived Sardinian and Ottoman troops.:461 The resulting battle of Tchernaya was a defeat for the Russians, who suffered heavy casualties. Question: Who was defeated at the battle of Tchernaya?

Output: the Russians

Input: Consider Input: Passage: In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not have been produced by natural selection. He said some such features could have been by-products of adaptive changes to other features, and that often features seemed non-adaptive because their function was unknown, as shown by his book on Fertilisation of Orchids that explained how their elaborate structures facilitated pollination by insects. Much of the chapter responds to George Jackson Mivart's criticisms, including his claim that features such as baleen filters in whales, flatfish with both eyes on one side and the camouflage of stick insects could not have evolved through natural selection because intermediate stages would not have been adaptive. Darwin proposed scenarios for the incremental evolution of each feature. Question: Why did Darwin introduce a new chapter in On the Origin of Species in the sixth edition?
Output: to respond to criticisms of earlier editions