2. He smothered a yawn behind his hand. 他用手挡住嘴遮掩自己打哈欠。
3. His speech made me yawn. 他的演讲令我打哈欠。
英英解释
n.
1. an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom
2. utter a yawn, as from lack of oxygen or when one is tired
3. be wide open