求助TPO18阅读求解（附原题和文章部分）

Go2011GoUID: 3006241

原文句子是：【According to conventional theory, yawning takes place when people are bored or sleepy and serves the function of increasing alertness by reversing, through deeper breathing, the drop in blood oxygen levels that are caused by the shallow breathing that accompanies lack of sleep or boredom.】

meverickUID: 2955424

http://club.topsage.com/thread-2325479-1-3.html

Go2011GoUID: 3006241

2# meverick
Thanks