His expressions varied from poker-faced to blank.

他的表情在不露声色与茫然之间变幻不定。

Laughter is one of the most infectious expressions of emotion.

笑是最具感染力的感情表达方式之一。

These expressions are often used interchangeably, but they do have different meanings.

这些表达法经常可以互换使用，但它们的确有不同的含义。

We can use our eyes and facial expressions to communicate virtually every subtle nuance of emotion there is.

我们可以用眼睛和面部表情来如实地传达情感上的每一丝细微差别。

I can read Diana's thoughts from the changes in her facial expressions.

我能从戴安娜面部表情的变化看出她的想法。