Detailed Instructions: In this task, you will be given a passage, a question and a list of single-word events identified from the passage. The goal is to point out all events from the given event list that can answer the question. If a question is unanswerable or none of the events answer the question, output should be empty.
Q: Passage: Low prices and the high purity of the heroin has also encouraged drug traffickers to take the risk, Jin said. A two-week class began in the cities and prefectures of Urumqi, Kashi and Ili on Nov. 6 to educate policemen, custom officers, train staff and postmen about drug smuggling. Question: What happened before the two-week class began? Events: ['encouraged', 'take', 'risk', 'began', 'educate', 'train', 'smuggling']
A:
encouraged