A mask that's too tight, or has too many thick layers can actually force more air out the sides.

口罩太紧或有太多层实际上可以排出更多空气。

" I think the biggest challenge for state departments of transportation on the work force side are what wages they're able to pay, " said Jim Tymon, executive director for the American Association of State Highway and Transportation Officials.

美国州际公路和运输官员协会的执行理事吉姆·泰蒙说：“我认为，在劳动力方面，州交通部面临的最大挑战是他们能支付多少工资。”