马上要迎来8份的托福考试了，同学们都准备好了吗??出国留学网托福栏目为大家带来托福阅读材料之The Mystery of Yawning，希望对大家有所帮助哦!
托福阅读材料之The Mystery of Yawning
The Mystery of Yawning
哈欠谜团
P1: 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. 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. About the closest any research has come to supporting the tiredness theory is to confirm that adults yawn more often on weekdays than at weekends, and that school children yawn more frequently in their first year at primary school than they do in kindergarten.
难词解析：
conventional adj.传统的
yawning n. 打哈欠
function n. 作用
boredom n. 厌倦
accompany v. 陪伴
难句解析：
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.]
根据传统理论，当人们无聊或者困倦时就会打...