In the last 25 years , however , the accordion bellows have expanded again .
过去的25年里，手风琴的风箱又扩展了。
Yawning helps keep the brain cool , and the sinuses play a role in that process by acting as bellows , a new report suggests .
一份新的报道显示，哈欠能够帮助大脑保持凉爽，鼻窦在这个过程中所起的作用就像是风箱。
During yawning , the walls of the maxillary sinuses ( located in the cheeks on each side of the nose ) flex like bellows and help with brain cooling , according to the researchers .
这两位研究人员表示，在打哈欠时，上颌窦的壁部（位于鼻子两边的脸颊上）像风箱一样弯曲，帮助大脑降温。
Now , hack and co-author andrew gallup , of princeton university , propose that yawning causes the walls of the maxillary sinus to expand and contract like a bellows , pumping air onto the brain , which lowers its temperature .
It opened into the house , where the females were already astir , zillah urging flakes of flame up the chimney with a colossal bellows ; and mrs heathcliff , kneeling on the hearth , reading a book by the aid of the blaze .
