rock bottom (also rock-bottom)

• 1. 

  N-UNCOUNT If something has reached rock bottom, it is at such a low level that it cannot go any lower. 最低谷

  例：

  Morale in the armed forces was at rock bottom.

  那时军队的士气处在最低谷。

• 2. 

  ADJ A rock-bottom price or level is a very low one, mainly in advertisements. 底线的 (价格、水平) [表赞许]

  例：

  What they do offer is a good product at a rock-bottom price.

  他们真正提供的是一种以价格在底线的优质产品。