Task: Question Answering
Input (English): A drain cleaner consists of sodium hydroxide and aluminum. When the drain cleaner is added to water, bubbles of hydrogen are produced, and the solution becomes very hot. Which of these best describes what happens to form the bubbles when the cleaner is added to water? F  
 (A) chemical reaction (B) Condensation (C) A physical change (D) Evaporation
Output (English): A