1. That guy is a slippery customer.

那小子是个老油条。

与customer相关的短语：

slippery customer 狡猾的无赖汉；hot customer 脾气暴躁的家伙

rum customer 怪人，难对付的家伙；ugly customer 可怕之人，赖皮鬼

2. Sales are flat/slack.

销售平平。

3. When Greek meets Greek.

棋逢对手。

4. First loves are indelibly etched into our minds.

初恋刻骨铭心。

First love is engraved¹ on our mind forever.

5. It’s the jack² in office that causes problems.

小鬼难缠。

Jack in office 自命不凡的小官员，神气活现的小职员

6. He swears black is white.

他睁眼说瞎话。

7. That song is before the Flood.

那首歌太老了。before the Flood 上古时代（指《圣经》上诺亚时代的大洪水期）

8. She was a budding genius.

她是一颗冉冉升起的新星。

9. I don’t think you realize the enormity of the problem.

你不知道问题有多严重。

10. My conscience is restless.

我良心不安。