n.打呵欠

adj.裂開的；打哈欠的

動詞yawn的現(xiàn)在分詞形式.

Yawning is a sign that you are sleepy or tired. 打呵欠表示你困了或是累了。

The researchers found that those who breathed through the nose rather than the mouth were less likely to yawn when watching a video of other people yawning. 研究人員發(fā)現(xiàn)，在看別人打呵欠的視頻時，用鼻子呼吸的人比用口腔呼吸的人打呵欠的幾率要小。

Although we associate yawning with sleepiness and boredom, its function appears to be to wake us up. 雖然我們把打哈欠與睡意和厭倦聯(lián)系在一起，但打哈欠的作用似乎是使人清醒。