Preventive control includes all measures taken to prevent the introduction and spread of weeds. 预防性控制包括所有阻止杂草侵入和蔓延的措施。
But the birth of a labelling system for the control of compliance concerns, occur about genetically modified foods for sampling and analysis methods of research. 但标签制度的诞生也引起了对符合性控制的关注，由此出现了有关转基因食品抽样和分析方法的研究。
