@RidleyDM @DrLeanaWen Perhaps. Mandates don't mean people wear the crappiest mask either, so there is all sorts of uncertainty here. Most of the evidence base on which these policies are based are pretty loose on types of masks but suggest some benefit from broad use. Not the only path, I agree.
@也许是RidleyDM@DrLeanaWen。授权也不意味着人们戴着最糟糕的面具，所以这里有各种各样的不确定性。这些政策所依据的大部分证据都与口罩的类型有关，但都表明广泛使用口罩会带来一些好处。我同意，这不是唯一的途径。