In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Input: Consider Input: Factories in China often produce what type of gas in their emissions that acts as pollution?, Context: A dense wave of smog began in the Central and Eastern part of China on 2 December 2013 across a distance of around 1,200 kilometres (750 mi), including Tianjin, Hebei, Shandong, Jiangsu, Anhui, Shanghai and Zhejiang. A lack of cold air flow, combined with slow-moving air masses carrying industrial emissions, collected airborne pollutants to form a thick layer of smog over the region. The heavy smog heavily polluted central and southern Jiangsu Province, especially in and around Nanjing, with its AQI pollution Index at "severely polluted" for five straight days and "heavily polluted" for nine. On 3 December 2013, levels of PM2.5 particulate matter average over 943 micrograms per cubic metre, falling to over 338 micrograms per cubic metre on 4 December 2013. Between 3:00 pm, 3 December and 2:00pm, 4 December local time, several expressways from Nanjing to other Jiangsu cities were closed, stranding dozens of passenger buses in Zhongyangmen bus station. From 5 to 6 December, Nanjing issued a red alert for air pollution and closed down all kindergarten through middle schools. Children's Hospital outpatient services increased by 33 percent; general incidence of bronchitis, pneumonia, upper respiratory tract infections significantly increased. The smog dissipated 12 December. Officials blamed the dense pollution on lack of wind, automobile exhaust emissions under low air pressure, and coal-powered district heating system in North China region. Prevailing winds blew low-hanging air masses of factory emissions (mostly SO2) towards China's east coast.

Output: SO2

Input: Consider Input: People leave nonprofits because of?, Context: Competition for employees with the public and private sector is another problem that Nonprofit organizations will inevitably face, particularly for management positions. There are reports of major talent shortages in the nonprofit sector today regarding newly graduated workers, and NPOs have for too long relegated hiring to a secondary priority, which could be why they find themselves in the position many do. While many established NPO's are well-funded and comparative to their public sector competetitors, many more are independent and must be creative with which incentives they use to attract and maintain vibrant personalities. The initial interest for many is the wage and benefits package, though many who have been questioned after leaving an NPO have reported that it was stressful work environments and implacable work that drove them away.

Output: stressful work environments and implacable work

Input: Consider Input: Who provided food for the underground shelters?, Context: Public demand caused the government in October 1940 to build new deep shelters:189190 within the Underground to hold 80,000 people but were not completed until the period of heaviest bombing had passed. By the end of 1940 significant improvements had been made in the Underground and in many other large shelters. Authorities provided stoves and bathrooms and canteen trains provided food. Tickets were issued for bunks in large shelters to reduce the amount of time spent queuing. Committees quickly formed within shelters as informal governments, and organisations such as the British Red Cross and the Salvation Army worked to improve conditions. Entertainment included concerts, films, plays and books from local libraries.
Output: canteen trains