Youmayhaveheardadultssaytheyareuncomfortableinthemornin...
问题详情：Youmayhaveheardadultssaytheyareuncomfortableinthemorningwithoutacupofcoffee.Onereasontheymayfeelthatwayisthatcoffeecontainscaffeine(咖啡因).Caffeineappearsnaturallyincoffee,tea,andcocoabeans,w...