1. Number one 最重要的人（或事物）；最好的人（或事物）

eg: Many people consider themselves number one, the most important person.
很多人認(rèn)為他們自己就是最好的，是最重要的一個(gè)人。

2. Look out for/Take care of number one 先為自己著想，照顧自己的利益，為自己打算

One and only 絕無(wú)僅有的；獨(dú)一無(wú)二的；有名的

eg: They are always looking out for number one and taking care of number one. It is as if they are the one and only person on Earth.
他們總是先為自己著想，只關(guān)心自己的利益，就好像他們是地球上唯一的人。

3. Pull a fast one 欺騙，搗鬼

eg: Jim only won the game because he pulled a fast one on his opponent.
吉姆因?yàn)楦鷮?duì)手耍了手段，才贏了比賽。

4. One in a million 百萬(wàn)分之一，鳳毛麟角，百里挑一，佼佼者

eg: She's one in a million.
她是個(gè)百里挑一的人。

5. At one time 同時(shí)，曾經(jīng)

eg: At one time we met frequently.
我們過(guò)去常見面。

6. Roll up into one 合為一體；兼于一身

eg: She is a great person -- kind, thoughtful and intelligent -- all good qualities rolled up into one.
她是個(gè)很優(yōu)秀的女人——善良，體貼，聰慧——集所有可貴品質(zhì)于一身。

7. One good turn deserves another. 善須善報(bào)；要以德報(bào)德；好人應(yīng)得好報(bào)。

eg: If he does you a favor, you should do him a favor. One good turn deserves another.
如果他幫你的忙，那么你就應(yīng)幫他的忙，以德報(bào)德嘛。

8. Be/go back to square one 退回起點(diǎn)，從頭再來(lái)

eg: His papers were lost in the accident, so he had to go back to square one with the work.
他的論文在這次事故中弄丟了，只得從頭再寫。