课程咨询
托福培训

扫码免费领资料

内含托福全科备考资料

更有免费水平测试及备考规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

托福阅读句子插入题:The mystery of yawning

2015-08-21 16:49:51来源:网络

  【托福阅读题型:The mystery of yawning句子插入题】托福阅读中句子插入题是重要题型之一。根据托福阅读题型不同来进行专项练习,是短期提高托福阅读能力的有效方法。同学们需要多加练习哦!

  查看全部:托福阅读题型分类练习之句子插入题

  托福阅读句子插入题:The mystery of yawning

  Another flaw of the tiredness theory is that yawning does not raise alertness or physiological activity, as the theory  would predict. When researchers measured the heart rate, muscle tension and skin conductance of people before, during and after yawning, they did detect some changes in skin conductance following yawning, indicating a slightincrease in physiological activity. However, similar changes occurred when the subjects were asked simply to open their mouths or to breathe deeply. Yawning did nothing special to their state of physiological activity. 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. ■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. ■If the theory was correct, breathing air with extra carbon dioxide should have triggered yawning, while breathing pure oxygen should have suppressed yawning. ■In fact, neither condition made any difference to the frequency of yawning, which remained constant at about 24 yawns per hour. ■Another experiment demonstrated that physical exercise, which was sufficiently vigorous to double the rate of breathing, had no effect on the frequency of yawning Again the implication is that yawning has little or nothing to do with oxygen.(The mystery of yawning)

  Look at the four squares [■] that indicate where the following sentence could be added to the passage.

  This, however, was not the case

  答案见下一页:

托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料