Supervision is the regulation and restriction of the microeconomic subject by the government in order to achieve certain public policy objectives under the market economy. It is mainly through the entry, exit, qualification, price, and related to national health and life safety of the subject of specific industries and microeconomic activities. , Sustainable development and other activities to monitor and manage to achieve. According to the above definitions, which of the following are under the supervision of the government? ['Farmers adjust the types of crops they grow based on market forecasts.', 'Food produced by a food factory may contain harmful substances that exceed standards.', 'A home appliance company raised the sales price of its products.', 'Some residents use government guarantees to buy stocks.']