1. Expression ：hit pay dirt

Explanation 1：To get great riches. （发大财）

Example：After years of poverty, the writer hit pay dirt with his third novel.

经过多年的贫困生活，这位作家因第三本小说而成功发财了。

Jane's doing well. She really hit pay dirt with her new business.

Jane做得很好，她因新的生意而挣了一大笔钱。

John has hit pay dirt with his carpet cleaning business.

约翰因他地毯清洁业务而赚了大钱。

Explanation 2：To discover something of value. （发现有价值的东西）

Example： I tried to borrow money from a lot of different people. They all said no. Then when I went to the bank, I hit pay dirt.

我试着向许多不同的人借钱。他们都说不。然后当我去银行的时候，我发现了意外的收获。

At first, I wasn't that interested in that job. And when they told me what my salary would be, I realized that I'd really hit pay dirt.

一开始，我对那份工作不是很感兴趣。但是，当他们告诉我的薪水是多少的时候，我才意识到这份工作有价值。

One of my fondest memories was searching through my grandfather's attic when I was a kid, convinced that some day I would hit pay dirt.

我最美好的回忆之一是小时候在爷爷的楼阁里翻来翻去，因为我深信终有一天我会发现有价值的东西的。

2. Expression：make a killing

Explanation：To have a great success, especially in making money. （获得成功，挣大钱）

Example：Since you're going to make a killing, I guess lunch is on you.

既然你们快要发大财了，我想午餐就算在你的账上吧。

If word gets out of our intentions, the rascals now in power may well seize the opportunity to make a final killing!

要是我们走漏了风声，现在掌权的那批坏蛋很可能就把握机会，临了还捞一大笔！

We can make a killing on these toys if we're able to market them in time for the holidays.

如果我们能在节日及时在市场上销售这些玩具，我们就能靠它大赚一笔。

It's very rare for someone to make a killing on their first investment—it takes a lot of time and patience.

很少有人能在第一笔投资中就大赚一笔——赚大钱需要大量的时间和耐心。