This expression is used mainly in speech, not in writing.

　　這種表達主要用于口語，而不是書面語。

　　The course teaches students to avoid ambiguity and obscurity of expression.

　　這門課程教學生避免表達上的模棱兩可、含混不清。

　　Try to put a little more expression into it!

　　盡量注入更多的感情！

　　Freedom of expression is a basic human right.

　　言論自由是基本的人權。

　　The expression in her eyes told me something was wrong.

　　她的眼神告訴我出事了。