I find it difficult to be objective where he's concerned.

　　只要涉及他，我就難以做到保持客觀。

　　Our main concern is to provide quality customer service.

　　我們最關心的.是為顧客提供優質服務。

　　These, then, are the main areas of concern.

　　總之，這些是人們主要關注的方面。

　　The new regulations will be of benefit to everyone concerned.

　　新規章將使所有有關人員受益。