instruction:
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
question:
Who practices 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.
answer:
Over two million people

question:
Al-Battani's beliefs made him a?, Context: In astronomy, Al-Battani improved the measurements of Hipparchus, preserved in the translation of Ptolemy's He Megale Syntaxis (The great treatise) translated as Almagest. Al-Battani also improved the precision of the measurement of the precession of the Earth's axis. The corrections made to the geocentric model by al-Battani, Ibn al-Haytham, Averroes and the Maragha astronomers such as Nasir al-Din al-Tusi, Mo'ayyeduddin Urdi and Ibn al-Shatir are similar to Copernican heliocentric model. Heliocentric theories may have also been discussed by several other Muslim astronomers such as Ja'far ibn Muhammad Abu Ma'shar al-Balkhi, Abu-Rayhan Biruni, Abu Said al-Sijzi, Qutb al-Din al-Shirazi, and Najm al-Din al-Qazwini al-Katibi.
answer:
Muslim

question:
How do some of the past students still contribute to this day?, Context: While Harkness' original colleges were Georgian Revival or Collegiate Gothic in style, two colleges constructed in the 1960s, Morse and Ezra Stiles Colleges, have modernist designs. All twelve college quadrangles are organized around a courtyard, and each has a dining hall, courtyard, library, common room, and a range of student facilities. The twelve colleges are named for important alumni or significant places in university history. In 2017, the university expects to open two new colleges near Science Hill.
answer:
colleges are named for important alumni