仔細看看下面詞典上各詞的解釋
previous /?pri?v?s/ CET4 TEM4
1.ADJ A previous event or thing is one that happened or existed before the one that you are talking about. 前壹次的
例：
She has a teenage daughter from a previous marriage.
她有個出自前壹次婚姻的十幾歲的女兒。
2.ADJ You refer to the period of time or the thing immediately before the one that you are talking about as the previous one. 前壹個的
例：
It was a surprisingly dry day after the rain of the previous week.
這是繼前壹周的降雨之後出奇幹燥的壹天。
before /b?f?/ CET4 TEM4
1.PREP If something happens before a particular date, time, or event, it happens earlier than that date, time, or event. 在 (某日、某時、某事件) 以前
例：
Annie was born a few weeks before Christmas.
安妮在聖誕節前幾個禮拜出生。
Before World War II, women were not recruited as intelligence officers.
二戰前，女性不被征募為情報官。
2.CONJ Before is also a conjunction. 在 (某日、某時、某事件) 以前
例：
Stock prices have climbed close to the peak they'd registered before the stock market crashed in 1987.
股票價格已經快爬升到了1987年股市崩潰前的最高紀錄。
3.PREP If you do one thing before doing something else, you do it earlier than the other thing. 在 (做某事) 之前
例：
He spent his early life in Sri Lanka before moving to Canada.
移居加拿大前，他早年生活在斯裏蘭卡。
4.CONJ Before is also a conjunction. 在 (做某事) 之前
例：
He took a cold shower and then towelled off before he put on fresh clothes.
他穿上幹凈衣服之前，沖了個冷水澡，再擦幹身子。
5.ADV You use before when you are talking about time. For example, if something happened the day before a particular date or event, it happened during the previous day. (某時、某事) 以前
例：
The war had ended only a month or so before.
戰爭大約在壹個月前才結束。
6.PREP Before is also a preposition. (某時、某事) 以前
例：
It's interesting that he sent me the book twenty days before the deadline for my book.
有趣的是，在距離我書的截止日期20天前他把那本書寄給了我。
7.CONJ Before is also a conjunction. (某時、某事) 以前
例：
Kelman had a book published in the U.S. more than a decade before a British publisher would touch him.
科爾曼在美國已經出版了壹本書，十多年後英國的出版商才願意出版他的作品。
8.CONJ If you do something before someone else can do something, you do it when they have not yet done it. 在 (某人能做某事) 之前
例：
Before Gallacher could catch up with the ball, Nadlovu had beaten him to it.
在加拉赫能接住球之前，納德洛夫就已經比他先接到了。
9.ADV If someone has done something before, they have done it on a previous occasion. If someone has not done something before, they have never done it. 以前 (做過某事)
例：
I've been here before.
我以前來過這兒。
I had met Professor Lown before.
我以前見過勞恩教授。
10.CONJ If there is a period of time or if several things are done before something happens, it takes that amount of time or effort for this thing to happen. 經過 (壹段時間或努力) 才
例：
It was some time before the door opened in response to his ring.
他按過門鈴後好壹會兒門才打開。
11.CONJ If a particular situation has to happen before something else happens, this situation must happen or exist in order for the other thing to happen. 在 (某事發生) 之前 (另壹情況必須發生)
例：
There was additional work to be done before all the troops would be ready.
在全軍準備就緒之前還有些事情要做。
12.PREP If someone is before something, they are in front of it. 在 (某物) 前面
例：
They drove through a tall iron gate and stopped before a large white villa.
他們開車穿過壹扇高高的鐵門，然後停在了壹幢白色大別墅前。
13.PREP If you tell someone that one place is a certain distance before another, you mean that they will come to the first place first. 在 (某地) 前方 (某距離處)
例：
The station is on the right, one mile before downtown Romney.
車站在右側，羅姆尼市中心前方壹英裏處。
14.PREP If you appear or come before an official person or group, you go there and answer questions. 在 (人或組織) 面前 (回答提問)
例：
The governor will appear before the committee next Tuesday.
這名行政官員將於下周二面對該委員會回答提問。
15.PREP If something happens before a particular person or group, it is seen by or happens while this person or this group is present. (發生) 在 (某人、某組織) 面前
例：
The game followed a colourful opening ceremony before a crowd of seventy-four thousand.
緊隨壹場精彩的開幕式，該比賽在7.4萬名觀眾面前拉開了帷幕。
16.PREP If you have something such as a trip, a task, or a stage of your life before you, you must do it or live through it in the future. (必須經歷的事情) 在 (某人) 面前
例：
Everyone in the room knew it was the single hardest task before them.
屋子裏每個人都知道這是擺在他們面前的壹項最艱巨的任務。
17.PREP When you want to say that one person or thing is more important than another, you can say that they come before the other person or thing. (重要性) 以…為先
例：
Her husband and her children came before her needs.
她的丈夫和孩子們比她的需要更重要。
before
[b?'f?]
prep. 在…之前，先於
conj. 在…以前；在…之前
adv. 以前；在前