2--What does this phrase mean? Let's find out.
 
1--There's no need for you to pay $20 for that hair brush, it's too expensive.
 
2--Why not? I really need it.
 
1--The store down the street has them at a dime a dozen! Come on, I'll show you.
 
2--When you say something is "a dime a dozen," it means that there's a lot of it, it doesn't cost much, or that it isn't special.
 
1--It's a dime a dozen. This is a common way of saying that something is so easy to get that it doesn't have much value.
 
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注解：
 
1.probably可能
2.expensive昂贵的 
3.common常见的 

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译文：

1--如果你听过美式英语，你可能会听过这个“It's a dime a dozen”（一毛钱一打）？
2--这是什么意思呢？让我们一起来看看吧。
1--没有必要花20刀买那把毛刷。太贵啦。
2--为什么呢？我真的需要它。
1--街边的那个商店也有，便宜到一毛钱一打（a dime a dozen）。快来，我带你去。
2--当你说某物是“一毛钱一打”（a dime a dozen）时，意思是有很多这种东西，不会花很多钱，或者是这种东西没什么特别的。
1--这一毛钱一打。（It's a dime a dozen）这是一种很常见的表达方式，说明某物很容易获得没有太多价值。