@theLUCASTDS @alexmeshkin These charts are kind of made up but I think this one comes from the assumption of close contact (notice 15 minute time for "no masks"). If the infectious student is not too close and there is good ventilation, you should still be fine.
@theLUCASTDS @alexmeshkin 这些图表是编造的，但我认为这个图表来自密切接触的假设（注意“不戴口罩”的时间为 15 分钟）。如果被传染的学生不是太靠近并且通风良好，你应该还是没问题的。