She turned luxuriantly on her side, yawning.

她打着呵欠，舒适地转身侧向一边。

He stood yawning, his pyjama jacket gaping open.

他敞开睡衣站着打呵欠。

He called, yawning and rubbing his eyes.

他打着哈欠，揉着眼睛，喊道。

No time had been found for yawning that day, either!

那天也没人有时间打呵欠！

Yawning is distracting, consumes energy and takes time.

打呵欠会分散注意力，消耗精力，耗费时间。

Yawning bore no relationship to sleep patterns, however.

然而，打哈欠与睡眠模式没有关系。

Yawning did nothing special to their state of physiological activity.

打呵欠对他们的生理活动状态没有什么特殊的影响。

The occupants of the rooms are yawning, or else scratching themselves.

房间里的人在打哈欠，或者在替自己搔痒。

Both men presently fell to yawning, and Injun Joe said: "I'm dead for sleep!"

两个人随即打了个呵欠，印第安·乔说：“我困得要死了！”

Again the implication is that yawning has little or nothing to do with oxygen.

这再次暗示着打哈欠与氧气几乎没有关系。

Support for this theory came from a study of yawning behavior in everyday life.

这一理论的支撑来自对日常生活中打哈欠行为的研究。

Will you be kind enough to give a penny to a poor boy who is yawning from hunger?

你可以给一个因饥饿而打哈欠的可怜孩子一个便士吗？

A growing body of research now shows that yawning is nature's way of keeping our brains cool.

越来越多的研究表明，打哈欠是一种让大脑保持冷静的自然方式。

It has been suggested that yawning and hiccupping might serve to clear out the fetuses airways.

有人提出，打哈欠和打嗝可能有助于清理胎儿的气道。

It might be that yawning helps to clear out the lungs by periodically lowering the pressure in them.

打哈欠可能通过周期性地降低肺部的压力来帮助清理肺部。

Another flaw of the tiredness theory is that yawning does not raise alertness or physiological activity, as the theory would predict.

疲劳理论的另一个缺陷是，打哈欠并不能像该理论所预测的那样，提高警觉性或生理活跃度。

Their yawning seems to have nothing to do with sleepiness or boredom—quite the reverse—but it does precede a change in activity level.

他们打哈欠似乎与困倦或者无聊没有任何关系，但恰恰相反，打哈欠这一行为的确出现在了活动水平的变化之前。

Experiments have also cast serious doubt on the belief that yawning is triggered by a drop in blood oxygen or a rise in blood carbon dioxide.

对于打哈欠是由血液中的氧气减少或血液中的二氧化碳增加引起的这种观点，一些实验也同样提出了严重的质疑。

The empirical evidence, such as it is, suggests an altogether different function for yawning—namely, that yawning prepares us for a change in activity level.

很多实验证据证实了打哈欠的另一个不同的功能，它能让我们做好准备，改变活动状态。

If the theory was correct, breathing air with extra carbon dioxide should have triggered yawning, while breathing pure oxygen should have suppressed yawning.

如果这个理论是正确的，那么吸入含有额外二氧化碳的空气应该会引起打哈欠，而吸入纯氧应该可以抑制打哈欠。

Volunteers were told to think about yawning while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide.

当志愿者在正常的空气中、纯氧的环境下，或者混有超过正常的二氧化碳含量的空气中呼吸时，他们被要求要想着打哈欠。

Volunteers were told to think about yawning, while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide.

当志愿者在正常的空气中、纯氧的环境下，或者混有超过正常的二氧化碳含量的空气中呼吸时，他们被要求要想着打哈欠。

Another experiment demonstrated that physical exercise, which was sufficiently vigorous to double the rate of breathing, had no effect on the frequency of yawning.

另一项实验表明，体育运动——尤其是剧烈的运动——可以使呼吸频率增加一倍，但这对打哈欠的频率没有影响。

A completely different theory holds that yawning assists in the physical development of the lungs early in life, but has no remaining biological function in adults.

另一种完全不同的理论认为，打呵欠有助于生命早期肺部的生理发育，但对成年人没有任何剩余的生理功能。

Unfortunately, the few scientific investigations of yawning have failed to find any connection between how often someone yawns and how much sleep they have had or how tired they are.

不幸的是，少数针对打哈欠的科学调查未能发现人们打哈欠的频率与他们睡觉时长和疲劳程度之间有任何联系。

There's a yawning gap between rich and poor.

贫富之间有一条鸿沟。

"I will put him to sleep," Mary said to the yawning nurse.

“我来让他睡着。”玛丽对打着哈欠的奶妈说。

Do you know how it is when you see someone yawn and you start yawning too?

当你看到有人打哈欠时，你也会开始打哈欠，你知道这是怎么回事吗?

Yawning may be part of that.

而打哈欠就是其中一部分。