Extract the answer to the question from the following context. Question: What effect do clouds have on SODIS? Context: Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours. Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions. It is recommended by the World Health Organization as a viable method for household water treatment and safe storage. Over two million people in developing countries use this method for their daily drinking water.
Ans: Exposure times

Extract the answer to the question from the following context. Question: What is the main idea of the passage? Context: The names for the nation of Greece and the Greek people differ from the names used in other languages, locations and cultures. Although the Greeks call the country Hellas or Ellada (Greek: or ) and its official name is the Hellenic Republic, in English it is referred to as Greece, which comes from the Latin term Graecia as used by the Romans, which literally means 'the land of the Greeks', and derives from the Greek name . However, the name Hellas is sometimes used in English as well.
Ans: names for the nation of Greece and the Greek people differ from the names used in other languages, locations and cultures

Extract the answer to the question from the following context. Question: How expensive are forced child laborers? Context: On 23 June 1757, the English East India Company defeated Siraj-ud-Daula, the Nawab of Bengal, in the Battle of Plassey. The British thus became masters of east India (Bengal, Bihar, Orissa) a prosperous region with a flourishing agriculture, industry and trade. This led to a large amount of children being forced into labour due to the increasing need of cheap labour to produce large numbers of goods. Many multinationals often employed children because that they can be recruited for less pay, and have more endurance to utilise in factory environments. Another reason many Indian children were hired was because they lack knowledge of their basic rights, they did not cause trouble or complain, and they were often more trustworthy. The innocence that comes with childhood was utilised to make a profit by many and was encouraged by the need for family income.
Ans: cheap

Extract the answer to the question from the following context. Question: When was Prince Albert in France? Context: In February 1918, he was appointed Officer in Charge of Boys at the Royal Naval Air Service's training establishment at Cranwell. With the establishment of the Royal Air Force two months later and the transfer of Cranwell from Navy to Air Force control, he transferred from the Royal Navy to the Royal Air Force. He was appointed Officer Commanding Number 4 Squadron of the Boys' Wing at Cranwell until August 1918, before reporting to the RAF's Cadet School at St Leonards-on-Sea where he completed a fortnight's training and took command of a squadron on the Cadet Wing. He was the first member of the royal family to be certified as a fully qualified pilot. During the closing weeks of the war, he served on the staff of the RAF's Independent Air Force at its headquarters in Nancy, France. Following the disbanding of the Independent Air Force in November 1918, he remained on the Continent for two months as a staff officer with the Royal Air Force until posted back to Britain. He accompanied the Belgian monarch King Albert on his triumphal reentry into Brussels on 22 November. Prince Albert qualified as an RAF pilot on 31 July 1919 and gained a promotion to squadron leader on the following day.
Ans: closing weeks of the war