378. As you sleep you pass through a sequence of sleep states-light sleep, deep sleep and REM(rapid eye movement) sleep -- that repeats approximately every 90 minutes.

英語四級譯文:
你睡覺時會經歷一系列連續的睡眠階段—輕度睡眠、深度睡眠以及REM(眼部快速運動)睡眠--這些睡眠階段大約每90分鐘重復一次。

四級詞匯講解:
as此處引導的是時間狀語從句，意為“正當……時，隨著”。如:
I saw you as I was getting off the bus.我要下公交車的時候看到了你。

pass through意為“經過”。如:
I came to say hello as I was passing through.我路過此地，順便來跟你打個招呼。
He passed through a difficult period after the divorce.他離婚后經歷了一段困難時期。

a sequence of意為“一系列，連續的”。如:
I was confused by a sequence of dance movements.我被連續的舞蹈動作給弄迷糊了。

英語四級考點歸納:
pass的常見短語有:

※ pass away意為“死”，是委婉的表達，相當于中文的“去世”。如:
Her grandfather passed away last year.她的祖父去年去世了。

※ pass sth. down意為“將某物代代相傳”。如:
Such knowledge should be passed down over the centuries.這樣的知識應該世代相傳。

※ pass over sth.意為“忽略某事物，回避某事”。如:
She chose to pass over his rude remarks.她選擇對他的粗話不予理會。