专题10 阅读、完形、语法填空、书面表达组合练-攻克2021年中考新题型英语语篇训练

语篇专题练习（十） 一、阅读理解 A Yawning is something we all do—maybe because we're bored carrying out tedious tasks or because we're tired．Sometimes, just seeing other people yawning can also make you yawn． But is this biological function really contagious, and why do we do it? Many of us think we open our mouths when we yawn to take in more oxygen, but in fact, there is no clear biological reason．According to BBC Bitesize, new research suggests it might be because yawning cools the brain down and prevents it from being too hot, much like the fan in your laptop．This might be why we're more likely to feel sleepy and yawn in warm temperatures． What is clear is that we yawn more when we're tired and ready for going to bed, and we can't control when we do it—once we start, there's no stopping us! But it's also true that yawning is a very contagious behavior．John Drury, a researcher from Sussex University, told the BBC that“it's meant to be senseless; it's something that you can't stop．Dogs yawn when