I don’t know what the answer above is. 2017 is the period of sample rotation for the national household survey held every five years. Therefore, survey team staff from various places of the National Bureau of Statistics will come to your doorstep with a letter from the household survey. , of course it is true. The household survey is a nationwide sample survey conducted on a household basis. It mainly uses questionnaires and cash journals to conduct direct surveys to obtain direct data on the living standards of urban residents across the country. If you are not sure, you can use Baidu