According to the cleaning levels, which of the following is classified as heavy cleaning?

Heavy cleaning generally refers to tasks that require significant effort and thoroughness due to the extent of dirt, mess, or unsanitary conditions present. Among the options given, items like human or animal waste, grease-covered walls, and even clothing and broken appliances can involve varying degrees of cleaning difficulty. However, when focusing on what typically constitutes "heavy cleaning," human or animal waste stands out due to health hazards and the extensive measures required to clean and sanitize any area contaminated by such waste.

Heavy cleaning involves addressing more severe issues associated with hygiene and cleanliness standards. This includes cleaning scenarios that pose risks to health and safety, which are exemplified by human or animal waste. Cleaning this type of contamination usually demands specialized techniques and equipment to ensure that the area is not only clean but also sanitized, making it critical in preventing the spread of disease or infection.

Therefore, while clothing and broken appliances may require a good amount of effort to clear and organize, they do not represent the same level of sanitary concern as human or animal waste, which is why this choice is deemed incorrect in this context.