Mix-up 是名词如：Oh, no! The student was sent to the wrong school. Sorry about the mix-up!
而你的例子中mix up时动词组合
mix up是个名词吗? 可是它在这些句子中的结构不是充当动词吗?比如：Don't mix up this pair o
Mix-up 是名词如：Oh, no! The student was sent to the wrong school. Sorry about the mix-up!
而你的例子中mix up时动词组合