阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
Starting from Nov 1, 2020, people will be knocking on doors across the country to collect personal information. This is for the seventh national population census (人口普查). China 1． (conduct) a national survey every 10 years since the 1990s.
2． (track) down more than 1 billion Chinese citizens is by no means easy. This year, about 7 million staff will be needed to visit homes for registration work. New methods will also be used during this census, 3． (include) online information registration, 4． (apply) of electronic devices and big data, 5． will be convenient for people who are not living where they are 6． (official) registered, as well as those who do not want 7． (bother) by door-to-door surveys.
The data is expected to give 8． full picture of the population. It provides support for making national development policies. The census has a large effect on our lives. For instance, areas with a high number of children may receive more funding for public schools.
However, citizens' privacy concerns could be one of the 9． (big) challenges. Some may not be willing to give their personal information to census takers. In response to such concerns, Jiangsu's pilot work zone allowed residents to upload personal data on 10． own through WeChat. The data will be delivered directly to the National Bureau of Statistics through a WeChat program.
