@loisrp @JimRosenthal4 @LazarusLong13 When on the ground ventilation is often minimal, regardless of how many times Leana Wen or Joseph Allen writes about not needing masks on planes. You're on your own. Use a good mask and don't take it off.
@loisrp@JimRosenthal4@LazarusLong13当地面上的通风通常很少时，不管Leana Wen或Joseph Allen写了多少次飞机上不需要口罩。你只能靠自己了。使用好的口罩，不要摘下。