Please answer the following question: Question: "How does the sun come into contact with bottles when using 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:
Answer:
exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight