Question

robert koch discovered that hot steam can be used to kill micro organisms. this process is called: disinfection sterilization pasteurization distillation harmful bacteria are responsible for changing cabbage into sauerkraut or kimchi making milk into yogurt and cheese

Explanation:

1. For the first question: Robert Koch's use of hot steam to kill microorganisms refers to sterilization, which eliminates all forms of microbial life (including spores). Disinfection reduces but does not eliminate all microbes; pasteurization uses mild heat to reduce pathogens (not full sterilization); distillation is a separation process, not microbial killing.
2. For the second question: The options shown (sauerkraut/kimchi, yogurt/cheese) are made by beneficial bacteria, so the question likely has missing harmful effect options. However, based on standard context, harmful bacteria cause issues like dental decay (implied by the dental image) or food spoilage, but since only the two options are visible, the question may have incomplete display. Assuming the intended correct harmful effect (though not fully shown), but for the visible options, neither is harmful—this suggests a display issue. However, if forced to address the first visible question fully:

Answer:

1. B. Sterilization
2. (Note: The second question's visible options are beneficial bacterial processes; complete options may be missing. If assuming the intended harmful effect, e.g., dental cavities (implied by the dental image), but as per visible content, no correct harmful option is fully displayed.)