In contrast, Manser says, a person's passive vocabulary consists of the words whose meanings they knowâso that they do not have to look the words up in a dictionaryâbut which they would not necessarily use in ordinary conversation or writing (The Penguin Writer's Manual, 2004).
Sleep Apnea, Night Terrors, and Nightmares. Sleep apnea may also be to blame for your nightmares. During sleep apnea, your brain senses the low oxygen and realizes that you are under a very real threatâyou are being choked or smothered by your own bodyâand if nothing is done you will die.
I am a 30-year-old woman. â January 12, 2012. Low blood oxygen, known as hypoxemia, means that the level of oxygen in the blood has fallen below normal levels, due to one or more of many different causes. Under most circumstances, breathing room air, normal readings range from 95 to 100 percent.