@jfeldman_epi In terms of "why did such and such place have masks and still have a surge", a 12% reduction is only going to "prevent" a surge in a the narrow case where R is between 1 and 1.12. Most surges trigger with R well above that.
@jfeldman\u epi关于“为什么某地有面具，但仍有激增”，减少12%只会“防止”在R介于1和1.12之间的狭窄情况下的激增。大多数浪涌在R远高于R时触发。