What are the possible links between facial expressions and emotion?

　　面部表情和情緒之間可能存在哪些聯系？

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

　　我能從戴安娜面部表情的變化看出她的想法。

　　Students should not worry about when exactly to use certain expressions.

　　學生不必擔心什么時候使用某些特定的表達。