第一部分 阅读理解(共两节，满分40分)
第一节(共15小题，每小题2分，满分30分)
阅读下列短文，从每题所给的四个选项A、B、C和D中，选出最佳选项。
A
While most people are suffering from snoring (打鼾)，research shows it can be harmful to your health.That's because for over 18 million Americans，it's related to obstructive sleep apnea (OSA)(阻碍性睡眠)．It can cause people to suffer from OSA repeatedly and unknowingly stop breathing during the night.The lack of oxygen can last for a minute or longer，and happen hundreds of times each night.
