中国农业普查事后质量抽查

The post enumeration survey (PES) of the First National Agricultural Census in China (NAC) was carried out in order to check the quality of the census data at the national level.A sample of about 40 000 rural households was enumerated,census and PES records were matched one to one,and census PES discrepancies on farm structure and management were computed.Almost 150 000 records of rural family members were matched,and individual response errors were computed.The most apparent errors on survey estimates were those of the interviewers.As far as respondents’ errors are concerned,it was determined that most of the census data are highly reliable,both at the farm and individual levels but some of the figures should not be published at the provincial or lower levels.Indications for future activities are given.

学好生物四步曲

升入初中的同学将学习一门崭新的课程——生物。要想学好生物，除了重视它以外，还必须掌握科学的学习方法：达尔文说过：“最有价值的知识是关于方法的知识。”同学们一旦掌握了学习生物的方法，就一定能轻松、愉快地学好生物。