What are the possible links between facial expressions and emotion?
面部表情和情绪之间可能存在哪些联系？
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。
Students should not worry about when exactly to use certain expressions.
学生不必担心什么时候使用某些特定的表达。