Brass tacks是“铜钉”，这个短语是什么意思呢？请看对话：

    A: We have other customers on the waiting list. If you don’t make a decision now, the car will go to someone else.

    B: Let’s get down to brass tacks. Who has the final say on the price and what is it?

    Note: This idiom means to “engage with the basic facts or realities.” This figurative expression isn’t particularly old. Its first appearance in print from the United States in January 1863 was in the Texas newspaper The Tri-Weekly Telegraph: “When you come down to ‘brass tacks’ — if we may be allowed the expression — everybody is governed by selfishness.” It may have come from the haberdashery trade. The notion is that, in order to be more accurate than the rough-and-ready measuring of a yard of material by holding it out along an arm’s length, cloth was measured between brass tacks which were set into a shop’s counter.