The brewing effect means that when a person is devoted to solving a certain problem for a long time and is puzzled if he temporarily stops to do something else, after a period of time, he may suddenly think of a solution. Which of the following are among the brewing effects:. ["Xiao Wang didn't find a file for a while, and after two hours he found the file.", 'Xiaofeng encountered difficulties in writing his graduation thesis. A few days later, he got a lot of relevant information when he attended the academic conference and cleared his thoughts.', 'A repairman consulted a lot of wiring diagrams while repairing the TV, and finally repaired the TV.', 'A researcher applied for a delay but did not get approval from the relevant department, he switched to other topics, and the project was approved after a few months.']