core parting line

例句：

1. 1. The company's core business is manufacturing electronics.
   这家公司的核心业务是制造电子产品。
2. 2. The heart of the matter lies in understanding the underlying causes.
   问题的核心在于理解根本原因。
3. 3. The core of his argument was that the economy would recover.
   他论点的核心是经济将会复苏。