Q: 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.
Passage: Singapore has doubled the avian flu tests on local and migratory birds from once every two weeks to once a week, Channel NewsAsia reported on Thursday. The measure is to monitor possible bird flu virus among some 20, 000 migratory birds flying into the city state during the winter months and to prevent local birds and poultry raised on farms from getting infected. Question: What started before the reporting? Events: ['doubled', 'tests', 'reported', 'monitor', 'flying', 'prevent', 'raised', 'infected']
A:
monitor