Finally, the authors conducted a final test using a special mask that allowed both nostrils to inhale, but forced incoming air to join together into a single air stream inside the middle of the nose.

• 最后一个，也是第五个试验，研究人员使用了一种特殊的面罩。这种面罩不会妨碍两个鼻孔的呼吸，但是会迫使吸进来的空气在被吸入鼻子以前混在一起，形成单股的气流。