) of yawning are still a mystery (谜). Scientists are not sure what causes a yawn. People yawn when... and your hair is a mess. Worse, you can’t stop yawning (打哈欠).Yawning is common to humans and many animals ……

is about 6 seconds.The purpose and cause of yawning are still a mystery. Scientists are not sure what... are bleary (模糊的) and your hair is a mess. Worse, you can’t stop yawning (打哈欠).Yawning is universal to humans ……

ancient map11. What is still a mystery about Zheng He’s voyage?A. The time of his last voyage.B... of how bad you may feel when you’re woken up in the morning?A. To lead into the topic of yawning.B ……

一团). Worse, you can’t stop yawning (打哈欠).Yawning is common to humans and many animals. Cats, dogs and fish yawn just like humans do.When you are yawning you open your mouth and breathe (呼吸) deeply ……

“乐呵呵”的海豹LOOK at the seal! He looks like he is smiling. A photographer took the picture at a beach in the UK. But in fact, the seal is not smiling. He is just yawning (打哈欠) to pass time. ……

我们为什么会打哈欠？词数 360 建议阅读时间 5分钟 测试见7版YAWNING is often the first thing we do when we wake up, and we... to yawning, so it has long been believed that the action makes us feel more awake by stretching (伸展 ……

you go to bed on time. Set your bedtime on the clock. Then, you can see a character yawning (打哈欠). Also, you can hear the sound of yawning. Are you sleepy now? ……

  One morning, I was walking toward the garage, yawning (打哈欠) sleepily... still like to see them around, especially when I’m stressed and bombarded with a lot ……

Leftover mystery boxes offer new ways to stop food waste                 Leftover mystery boxes offer new ways to stop food waste      ……

悬疑推理小说经久不衰的魅力是什么？Mystery novels were popular among readers when authors started writing them in the 1800s. Today they are just as popular, with many new mystery movies and TV series added ……

助他们提高听力理解能力的一个课堂实例，听力原文如下:Professor Robert Provine has been studying yawning for the past two years, but he says he still does not know why people yawn．In fact，no one seems to know much about it．Professor ……

that yawning is contagious (传染的). But why is that?In fact, yawning is not just a sign of sleepiness... or to understand the situation they are in.Contagious yawning shows that you share others’ feelings ……

? Perhaps this yawning (打哈欠) alarm clock can help. According to Canadian online design magazine Yanko...的) mechanical flipbook (翻页书) plays an animation of a character yawning. An audio clip of a yawn plays ……

Leftover mystery boxes help with food waste but still raise concernsLeftover mystery boxes help with food waste but still raise concerns“剩菜盲盒”：杜绝食物浪费的创新实践“剩菜盲盒”：杜绝食物浪费的创新实践词数 370 建议阅读时间  ……

“乐呵呵”的海豹LOOK at the seal! He looks like he is smiling. So cute! A photographer (摄影师) took the picture at a beach in the UK. But scientists say the seal isn't smiling. He is just yawning (打哈欠) to pass ……