1. 回籠覺
unprotected sleep
什麼叫unprotected sleep？字面上理解是無保護的睡眠或風險睡眠，指的是turning off your alarm clock and immediately going back to sleep; risking not waking up for a job, class, or other daily task. 冒著工作遲到的風險關掉鬧鐘睡回籠覺，這是不是很多人每天生活的真實寫照？
e.g. I'm lucky that I didn't miss my final exam after having 30 minutes of unprotected sleep.
我真走運，睡了30分鐘的回籠覺還沒錯過期末考試。
2. 自然醒
wake up naturally without alarm clock
有研究表明早上被鬧鐘吵醒容易造成神經衰弱現象，可是試問現在有哪個人早上不是被鬧鐘吵醒的?當然也有鬧鐘吵不醒的筒子們。ditch the alarm clock是需要很大勇氣的！
e.g. The second school says you should listen to your body's needs and go to bed when you're tired and get up when you naturally wake up.
另外一種觀點認為你應該按照你身體的需求，累了之後就睡覺，一覺睡到自然醒。
3. 那些關於「睡覺」的各種短語：
have a cat nap 打個小盹
doze off 打瞌睡
have a siesta 午睡
do not sleep a wink 一夜沒合眼
hit the sack 倒頭就睡
light sleeper 睡覺輕的人
sleep around the clock 睡了一整天
caught napping 毫無準備，措手不及
e.g. Louis was so tired that he hit the sack soon after supper.
路易斯太累了，所以吃過晚飯就早早上床睡覺了。
e.g. The neighbors were having a party and we couldn't sleep a wink last night.
鄰居舉行晚會， 吵得我們一夜都沒合眼。
e.g. I told my girlfriend that I'm a light sleeper, and that the slightest disturbance will wake me up.
我告訴我女朋友我睡覺很容易醒，最細小的動靜也會把我驚醒。
e.g. Their competitors are caught napping while they are responding to complex prospect requirements.
他們正在回應複雜的潛在客戶需求，而競爭對手卻措手不及。