呵欠连天

Explanation: Yawn: sleepy often open big mouth can not help but inhale the phenomenon. Constant yawning. ① describe not wake up. ② metaphor very tired look. Also as "Kazakh air grievances." 　　Source: ① Mingling 濛 early "first moment to stand up surprised," Juan Liu: "Spring Blossoms for up earlier, and nap in a small room, master, master of the house heard the woman called out the slogan, yawning and groaning, walked in front of." ② and Volume : "people are too dizzy wind Britain, all of them are yawning and groaning, unwilling to go with."